Ok, first of all, you should listen to your mom. Unless you're dealing with vermin, you don't shoot what you won't eat or use (like furbearers). Secondly, I think that you'd better check you state's game laws, because generally speaking there are no small game hunting seasons in the summer time. If it's not hunting season, and you shoot a game animal, then you're a poacher. Real hunters hunt legally. You also need to find out what kind of licenses you need, and if you need to take a hunters safety class, when the hunting season does come around in the fall/winter. Many non-game birds are also illegal to shoot all the time.

If you want a reactive target, they sell reactive airgun targets in a variety of configurations at any sporting goods store. Pop cans are another great and cheap reactive target to shoot at.

As for you scope, some cheap airgun scopes are just that, cheap. I don't know what kind of airgun your is, but I do know that the really cheap scopes don't handle the reversed recoil of spring powered airguns very well. There are good scopes out there that are made, but I'd imagine that they cost a bit more than $30. I also don't know how accurate your air rifle is. Have you tried shooting groups on paper with it at 25 yards or so? I had several airguns when I was a kid, and all but one wouldn't keep every shot on a beer can at 25 yards (I didn't shoot groups in those days).

Mike