I've got nothing but time for the next month (no job, live in the country, 16 y/o, summer vacation half-over.. bah!), so I NEED something to do, and thought about spud guns, did some searching, so I ended up here.
I just need some advice on what to do, I know NOTHING of guns, only experience I've got is shooting air rifles (not to brag, but I'm a pretty good sniper

I'm not too familiar with this kind of stuff (I'd fix crap around the house, assemble desks/shelves, etc. I'm good at taking stuff apart and reassembling, as I've been told so numerous times), but I know a little, my brother and dad are car nuts, so I've got pretty much every tool imaginable, and I've got a decent amount of money to blow, and access to free metal (any kind, although I don't know if that is useful info) as my dad works at a forge.
I don't even know where to start, big or small, combustion or pneumatic, etc, etc. Obviously I'm leaning towards combustion, but it's not like I won't do pneumatic. My yard is about 150 yards back, if that's useful or not.
Thanks in advance, fellas.