Welcome to TNET!
I will tell you what everybody told me when I first started. Hit the parks and tot lots. Make sure you check with the local authorities and follow their rules and get permission and or permits where required.
Here is a couple things I have found in a few short months I have been mding.
Kids love hanging upside down on playground equipment.
woodchips give up lots of coins quickly - not old ones but lots of clad (good for learning techniques)
don't necessarily think higher income area parks will give up more coins - I find more coins in lower income parks.
Read as many threads on this website as you can, you will learn a ton - go to the library and do research to find sites to search(simple rule of thumb I learned from somebody aaround here is 2 hrs research minimum for each hour in the field)
and finally if you are like the rest of us in the world,
Wait for the ground to thaw!