I was in your same situation. I got a LTCH almost as soon as I turned 18. My dad wouldn't buy me a handgun so I bought a H&K USP 9mm from an INGO member. Ammunition can be purchased from any store except Walmart pretty much. Say you have a hi point carbine or other rifle chambered in your handgun round and most places will sell to you. It's especially easy if you get a 357mag or another big round that is more common in rifles.