We got back from our first long-ish trip. One month down south. Our thing is visiting historical sites and museums, so we're constantly dealing with what to do with the trailer (26bh).
We use Walmarts a lot for overnights, but would never unhook while there. The only place we unhook is at a campground. So, for the most part we coordinate our museum visits with a stay in a local campground. Once in a while, we'll visit an attraction with the trailer in tow if they they have a large enough parking lot to accommodate us.
Which reminds me...that can be a great way to visit some places. Example: the Gilmore Car Museum near Kalamazoo, MI. The museum is big enough to spend a day there, so you have your trailer handy for lunch and breaks. Like having a car museum in your backyard.