I am not into camping so I’m in large urban, suburban, or small towns almost exclusively. My philosophy during the daytime is park where I am not a nuisance. Most people and establishments don’t care what I'm doing as long as I’m not interfering with what they are doing. I’ve learned this because my generator is in a 40’ class A, so it’s not stealth, it will always be noticed. I’ve never had problems hanging out in the parking lot of large malls, on the streets in industrial areas, city parks, the vacant lot of closed businesses, and gas stations that cater to trucks. When parked in any of these places I have an inviolable rule: I will never run my generator around people unless they are running one. This may mean parking at the far edge of a lot or on a low traffic street in an industrial area. At night I park in areas where RVs are welcome (or at least tolerated). I've had no problems running a generator at rest areas, welcome centers, truck stops, and RV dealerships closed for the night.
In my van, I opted for a large battery bank and alternator charging rather than a generator because I want it to look unoccupied (especially at night). But in cold weather, the noise from running a diesel heater thwarts this effort as much as a generator would. During the day, people don’t care if I’m in the van so I have no problem idling the engine or running the heater almost anywhere (away from pedestrians). In the van this includes busy streets in urban areas, small municipal airports, strip mall and big box parking lots. At night, I want to park somewhere where people don’t care or won’t notice the sound of my diesel heater. One of my favorite places are park & ride lots.
I always separate my hang out spot from my overnight spot. The same could be done when using a generator. For example, use it a the Walmart parking lot then drive somewhere else when finished.