Don’t be shy about asking for help. If it’s getting dark and you’re at the grocery store, yes, you DO want help out to your car. If the checker doesn’t offer, or if you are only buying an item or two, ask for an escort.
When I’m alone and need to walk through a parking lot or structure, I attach myself to a group. I did this recently at Comic Con when the only parking available for many blocks was in one of my least-favorite places, a high-rise structure.
Unfortunately, the only group I could find were Japanese tourists, and I made some hand gestures which I hoped meant “I’ll just walk with you, if that’s okay” but to them could probably have meant, “I really need to get back to the institution by sundown.”