Here are some of my methods:
Locate industrial area on google maps. Houses are tiny, but industrial areas pop out easy on satellite view (basically look for massive buildings, usually white roofs, and they usually take up several blocks so you cant miss them. Then locate areas with semis / vehicles parked on the sides of the street, ignore parking lots. There's a good chance other people sleep there as well but Its usually really quiet in my experience. I try to park next to an empty lot, or a gate or a wall, far as possible from entrances / doors to avoid being oogled by workers in the morning while I sleep (I'm in a car atm. You won't have to work as hard to find the best spot if you're in a van or something obviously.
google maps, search apartments. use satellite view to find apartments with street parking. I try to park near the end or beginning so fewer people will walk by in the AM but that's because I'm quite visible in my car haha.
When I had my van I used to park on residential streets that are lined with vehicles, especially if it looks so crowded that you can tell people park wherever they can as opposed to right in front of their house. You blend in on those crowded residential streets! Use satellite view on google maps, you can usually get an idea of good neighborhoods to try.
In bigger cities many times you can find people living in vehicles just off the highway exits. Not always available and sometimes sketchy af but it's fairly easy to use satellite view on maps and follow the highways and search near exits for clusters of parked cars and RVs.
I also look for parks with street parking via Satellite view which is a bonus because I walk my pup before I leave the next morning.
I love campendium.com but make sure you search " free (your state here)" because they have a ton of free campsites all over the US but not all of them are free. I think Colorado had like 250 free campsites for instance.
I've slept in hospital parking lots or street parking in front of a church in a pinch.
Just a note, if cars are parked roadside on maps satellite view there's a good chance there usually are people parked there so you will blend in.
I hope this helps you. I've gotten pretty good at finding spots through experience and generally not giving af. All they can do is make you leave so dont be afraid to try new things. hope my instructions were clear, I'm a little sleepy. Good luck and safe travels to you, friend.