Navy gave you some good advice, buy your bow at a pro-shop and have them set it up to fit you and tune it. Have the pro-shop also match you up with the proper arrows for you and your bow. You do not have to buy the most expensive bow in the shop in order to hunt with, but do not buy a Wally World special either, the majority of major bow manufacturers produce some darn fine affordable entry level bows.

You need to start practicing now for next season and I will be honest you can not practice to much but you can sure not practice enough.