And it'll take awhile, but check out the posts in General discussion too, thats where a lot of newcomers first go to ask questions. A lot of valuable information in the answers!
Hey kid, I'm in Iowa too. Parks would probably be a good place, state parks, school yard if you behave and bury the holes back up. I hunt around old farmstead areas but my favorite is to wait till I go on vacation and detect in Florida.
Have fun and congrats for finding a worthwhile hobby!