I often see folks working on their vehicles in the parking lots of the auto parts stores. As long as you're buying parts from the store and are respectful of their property they don't seem to mind. Some stores will rent, or even loan you tools while you're doing a repair in the parking lot...........One evening, while I was on the road working construction, I did a complete rear brake job in the parking lot of an O'Reilly's.
Once, while working on the road I changed my truck's oil in the workplace parking lot. I used a small plastic tub, a funnel, and a couple of plastic jugs to retain the old oil, and some rags and a large piece of cardboard to retain the mess. Proper disposal of the old oil could be problematic, but fortunately most auto parts stores and service centers will freely accept used engine oil and filters......... I think they get a tax break or something for doing so.