My favorite, though, has been https://freecampsites.net/ which has helped me find a bunch of really beautiful free spaces to camp. I've used these tiny campgrounds on Maine public lands a lot.  They list and review places from campgrounds like these to Walmart (which ones permit camping) and rest areas.

One of my favorite things about the pod this year is that I was not trapped at home but I could still stay safe.  I almost never say it because I feel a little guilty while others are suffering, but I've had a great summer.

Also consider the time of year. If you are in a rest stop or parking lot you won't be able to run your a/c unless you get out your generator, that's where the big RV's with built in gennys have an advantage.

If we're on a trip through to a destination we will often just get a hotel room for the occasional night.  No setting up and braking camp, cooking, cleaning. The a/c works, grab the free breakfast in the morning, get an early start.  Take a hot soak in a tub if your back is stiff from driving all day. Use that evening to do the laundry without having to hang out at a laundromat. Saves the camping for the nice camping destination. 

Depends on the area as far as walmarts etc go.. Some municipalities don't allow it. There are some active groups and apps that can be used for tips and tricks, "boondockers welcome" is one.

We have always just found a CG along the way. We boondock, not as much as we used to, but that's always been the destination, rather then a waypoint.

we go to the beach for the holidays every year, halfway there, we get a FHU site in a year 'round park, it's about $30, easy in and out, no troubles, no hassles. They even like our dog.. LOL Same thing coming home in January, we usually winterize there. Then finish the drive.