I have never loaded .45 Long Colt but I would guess some 2400 or H110/296 or even BlueDot would get the most out of the cartridge.
I would suggest calling around local gun shops for some powder and go with one of the bullets these guys suggest. You would have to get your parents to make the purchase since you are blessed with youth! If money is a problem, I'll make a donation to a very worthy cause of an up and coming handgun hunter! No doubt others here would do the same. Just gotta keep it legal.