The best place to start is in your own yard! Especially good if you live in an older place! When I first got my MD, I hit my yard multiple times and found items everytime - including a silver ring, a silver quarter, several wheat pennies and of course, lots of 'junk'!
If you have family or neighbors you feel comfortable asking, see if you can hit their yards. Also, check your local laws/rules for detecting in the parks and other public places (swim holes, fairgrounds, ballfields, etc). Where people gather is where you'll find stuff - like on a beach!
Good luck and be sure to post your finds!