First, fill out your profile, including age and where you live. If you are 18, find out which age verifier is closest to you. There is a stickied thread with a list somewhere around here.
If you are not 18, then you've got time on your hands to wait until you are 18. You can't buy a gun until you are 18. Read through all of the FAQs, and start doing research about different guns you are interested in.
Welcome to the sport.
I love freedom and consequently America