How noob are you? Do you own and shoot a l'il ol' .22? Best bang for your buck for learning: cheap ammo, low recoil, accurate at shorter ranges. I'd start there.
However, my $0.02 on topic is learn to shoot the .223 really well, then start fiddling around with modified/"esoteric" cartridges. Plus, you can buy factory .223 over the counter, whereas .223AI you'd have to hand-load. Now you're into a whole different area, where variations in bullet/powder/primers/brass will affect accuracy. (Somebody correct me if they know of any manufacturer making .223AI)
and hey... if it hasn't been said, "welcome to CGN!" Nooub.