Parks, churches, and curb strips are the places I tend to hit.
Most of the parks in St. Pete where I live are OK to detect. There are a few that are historic sites that are off limits. In parks dig small holes, fill in your holes cleanly so that it is hard to tell you were there.
Churches can be good places to detect. I had a church permission with a big property that I hit for years. Of course you need to ask for permission first.
I take walks or drives in older neighborhoods. I look for sidewalk tear outs, homes about to be torn down or torn down and do the curb strips. If I see someone outside, I might ask permission to detect the property.
If you are up to it, I would recommend taking a drive a bit north to Brooksville. Look up Russell Street Park and park there. Next to the park there is a 1885 train station and across the street sits an 1800s house. If you walk north from the park the whole neighborhood is full of older homes. Being around the older homes inspires me to get out to do some detecting.
I will be in Springhill this weekend. At this point I am not sure if the family has anything planned but I suspect I might have Sunday open if you want to try to meet up somewhere.