There are lots of good prices on 22s. And I recently saw some very good prices on 22 revolvers from a vendor here. So a revolver and a pistol might be an idea as well.

Revolver would let you try a few different methods of target shooting as well. Indulge your inner Lone Ranger.

Of course, being GTA, getting the range membership taken care of might be the bigger purchase to deal with first (time & $$). And depending on your mobility, a rifle might be best to wait on. Go with what will be most convenient to shoot. Treat it like a gym membership. Best one is the one that's easiest to get to/use. Let's you meet the most peopl and learn the most, fastest.