I'm speaking from experience (although a little older...)
Make sure you take the time to visit a local shop and get properly fitted, instructed on shooting techniques and educated on all of the gadgets that come with this awesome sport. Also, more importantly, do a few push-ups and some arm stretches before your practice sessions. I haven't been able to shoot in 2 weeks due to a severely sore shoulder...I didn't stretch and found out I had "weak" shooting form.
I can't wait to start hitting those groups again!
Welcome aboard! You should find a lot of cool bowhunters here with a lot of helpful advice...