I would have to say a 22. I got a 20 gauge as my first hunting gun at about that age. For my age that gun had a pretty good kick to it, so I was a little hessitant about shooting it for a little while because after a few shots my shoulder was done lol. But eventually I got used to it and could handle it after a year or so my dad bought me a rifle a 30-30 to be exact. It was a little loud, but I loved it I would shoot it like crazy very low recoil, It is a brush gun so it will only shoot about 150-200 yrds accurate, but it was great. I really have rarely shot the 20 gauge since it pretty much sits in the gun cabinet. So I would have to go with the .22 or another caliber without such a long range