To be honest spots are, to an extent, what you make of them. Personally I started training behind some stores in a plaza nearby with just a wall some rails and some dumpsters. I train at a park near my old high school, and you'd be surprised how much fun you can have on playgrounds. More important than finding ideal spots is finding ways you can move in the places you have.
Also, climbing schools, at least near me, isn't a good idea because the cops tend to show up. It's best to avoid trespassing and really there isn't much to do on roofs once you get up there.
So really my advice is to keep your eyes open for places you can train and different ways to move with the places that you do have. One of the best parts about parkour is learning how to see different ways to move with the obstacles around you.
