I think that group size is far more important with a traditional bow than it is with a compound when it comes to hunting. If you can't shoot well with a traditional bow on a target, you need a better set up, better form, or more practice before you shoot your first arrow at an animal. A compound is much more easy to master so long as you shoot fairly well and your bow is tuned.
There's a J-curve and you start to lose the bang for your buck close in with a compound.
I consider "good shooting" for the average bowhunter with a compound as an inch for every 10 yards. You can certainly get better than that, but 2 inches at 20 yards and 6 inches at 60 are doable with practice and a tuned bow with anyone, IMO.
Personally, I insist on much better than that for myself and the distance that I limit myself to is closer than my group size on my target animal's vitals, but that's because animals are far more difficult to shoot than a target because of nerves and the fact that they move.
Still, for your first deer season, focus more on keeping your cool. What happens with a lot of bowhunters that haven't killed a lot of animals, is they hurry the shot and in the last second, just get the pin on the animal and fire and they end up missing or hitting the animal with a bad shot. Learn to slow down, take your time, and pause right before the shot so that you make a quality shot and if you are an average shooter, you're going to make an above average shot on your first bowhunted animal.
If the animal is moving or not going to give you enough time to make the shot, then learn to pass on the shot. It's better to let them walk than to hurry it and wound. The greener you are, the less likely you are to make a good shot when you don't have much time to drop the string.
If the animal sees you draw and is motioning away from you, consider just letting it go, especially if it's over 15 yards. The best shot for your first few bowhunted animals is an animal that has no idea that you've drawn on it.
Learning when to draw and release is a huge part of the art of bowhunting and differentiates bowhunting from rifle hunting more than anything else than the distance required to kill.
For your first few animals, everything should be as close to perfect as possible. But if you think you can kill it, kill it. Don't just wing an arrow at a passing animal. Missing and wounding will just bring doubt and will make you question yourself.
If you have it and you know you can kill it, do it. Tell yourself you're going to kill the animal and then pick a spot on the shoulder and focus on the job at hand and kill it. Every time you do it, it'll build confidence and experience and you'll be that much more prepared to do it the next time.
Build your muscle memory and relax. Run through your rhythm. Stance, sight picture, grip, anchor point, breath control, release, follow through.
Take an additional lesson or two to make sure that you're not developing any bad habits form -wise.
When the time comes, just do. Let it flow smoothly. Stay loose. Don't overthink or get stressed.
Be the arrow.
That's all the psychobabble I've got to avoid buck fever or target panic. It works for me, but there are lots of guys on this site more qualified than me to give you advice.
Edit : I was typing when they posted. What Ike and Ziek said too
Guys who claim 1" per 10 yards are not telling the whole story. I can shoot like this "most" of the time as well. But my group definition shows on the paper target I/We use in competition. Any hole in the paper that is more than 1" from the center of the X at 20 yards disqualifies said shooter from that accuracy claim. Go shoot 100 arrows over a few days time at the same paper target. Measure the arrow farthest from the center of the X and multiply that number by two. That is your actual group size at that yardage.
I can't remember the last time I shot a 4 on an indoor 300 score and my 20 yard group size is more like 4". I have seen 60X 300 scores(perfect) that would not qualify for 2" groups.
In summery, please strive for 1" per 10 yard groups but don't be discouraged if they are double that some days.
I'm usually happy when I can get all three arrows in a ~ 4" circle at 20yds.
Before my sheep hunt, my last 6 arrows were shot at 45 yards with broadheads and were all center of the bull's eye I was aiming for. That day I shot about 30 arrows and not one was outside of the 1 inch per 10 yards number from 20-80 yards. Mid trip after I missed a sheep high due to ranging the hill behind him instead of his back (therein lies the witchery of bowhunting, translating good shooting into a dead animal) I picked a softball-sized clump of dark tundra on a white tundra back and shot it from 50-70 yards about 15 times and hit it every time with one shot hitting the upper margin and one shot hitting 2 inches high on a 70 yard shot. None of my shots were in the bottom 1/3 of the clump.
Personally, even if I'm drilling the vitals 95+ out of 100 shots from 80 yards, I'm still not going to take an 80 yard shot. I also firmly believe that you should practice out to half-again, preferably twice the distance that you'd consider shooting an animal at. It makes the closer shots easier.
There's a difference between shooting a group consistently and "always." No one is 100% in anything, all the time. Even a strep test misses 1 in 10.
Back on topic to the OP, I'd encourage him to shoot at a lifesize deer target, out of a tree (or whatever he'll be hunting from), with broadheads. When he can no longer hit the vitals 9 out of 10 times, dial your max distance back 10-20 yards and have that be your max shooting distance, or something similar. Honestly, if it's your first deer, you don't want to be taking a long shot, even if you can do it. Closer shots are just higher percentage.
Don't take the majority of your practice shots at 20 yards, or even 20, 30, and 40. Shoot arrows at every single yard distance between 5 yards and up as far as you can while still hitting the target consistently. Deer don't circle trees at 20 and 30 yards. In fact, statistically, they'll be at a yardage other than an even 10 yard increment 9 out of 10 times.
heck...if I only count the "first" arrow I shoot each day while shooting at an animal target without a "spot", then I can claim a 5/16" group at every yardage ;)
What matters MORE, IMO, is whether you can hit a gallon jug every time or not, while never taking the same shot twice.
Under pressure.
JMO, Bad Idea for anyone to have more than one sight pin on his bow until he has made several clean kills at close range. And whatever your Fully Confident range is on targets, cut it in half for hunting. If there is any question whatsoever as to which pin to use, wait it out. If you’re too juiced to settle into your shot, wait it out. No blood, no foul, and another will be along soon enough.
Enough stuff goes wrong when everything is Perfect, so no need to push your luck. Nobody will starve, so no sense feeding the coyotes in an attempt to feed the Ego.
Shoot lots of different yardages, and angles don't get in the habit of just doing 10 yard increments! shoot at 9, 17, 28 and then 33, 37, 46 etc... quartering too and away, You will become a much better shot and hunter than just punching X's at 20 or 30 yards broadside. Look at where the arrow would have gone in and out of an animal and adjust your aiming points accordingly to hit the vitals and miss heavy bones. A 3-D target is a must. even a cheap one is great!
Good advice above as well, have fun and go learn
Yes, yes I could. Miss-fires are different I suppose. Missing by six feet due to a miss-fire isn't going to wound an animal. Fliers that miss by six inches should definitely count.
If I remember correctly #1,823 went into your garage wall and #3,642 went over the garage and into the neighbor's roof. :)
The more I shoot the better I am. Automatic
Like Ike, I go by the 1" per 10 yard rule. Aim small-miss small.
Appropriate size dots help me to focus better, than a life size target. I do keep things scrambled and sometime shoot life size animals to make sure, I'm on target.
I also use a rangefinder at 3-D shoots to simulate actual hunting conditions. This further positively reinforces my mind about bow correctly sighted in, distances and hitting actual kill zones, not 3-D target zones.