I think legally you can't do those maneuvers in aircraft not rated for them. And unless you have your own plane I don't think any FBO in their right mind will let you check out an aerobatics capable aircraft without some sort of training.

P.S - I know you can do limited aerobatics in Utility class aircraft such as the 152. But they are very specific on what maneuvers you can do and I'm pretty sure it's limited to stalls and spins.