Hmm.
I'll go with my gut here, and recommend that nirvana not listen to lasersailor on anything gun related

Get a .22 and shoot the heck out of it. Get a .22 pistol too, when you're able to. Practice and have fun with it. Then do your research and decide if you want a more powerful gun. If you do, you should think about WHY you want a more powerful gun. Then find the gun and round that matches what you want, and then buy that one.
Buying a powerful gun just to be manly is something a gun nut or "enthusiast" does... But if you want to be a "shooter", put a little thought into it first. In the meantime, shoot the hell out of the .22 'cause they're cheap, fun, and you can learn a lot of good techniques and habits with them. Buy something bigger when you think you need one, not because somebody tries to question your manhood over the size of your gun. There's always some tool out there with a bigger gun, so the earlier you get over caliber envy the happier you'll be

That said, my recommendation for a nice "second rifle" is a .223. Most of them kick enough to teach you about recoil, they can be used for both light hunting and plinking since .223 ammo is cheap, and there are a lot of options out there from bolt action to autos. I have a ruger mini-14 and it's nice and rugged but it isn't very accurate. Some of the M-16 variants are much more accurate but because they look scary, some states have banned them and that means they are typically very expensive. A bolt action .223 would be a good intro to hunting rifles and a lot cheaper to practice with, but to be honest I wouldn't even hunt deer with a .223 because of the possibility of making non-lethal shots if you don't get your shot placement just right. But I have a .223 to practice with because it's loud enough and has just enough recoil to keep my natural flinching reaction completely under control, so I don't flinch when firing my real hunting rifle, a 7mm Rem Mag Browning A-Bolt.