My niece lives on her own and has $4000 to spend on a car. Her 2004 Honda Accord was totaled by a city street sweeper! With a $4000 budget I was thinking of a Toyota Corolla, Honda Civic, or even an older Toyota Camry. She uses her car to commute to work and also does DoorDash part time.
Suggestions?
Any of those would be OK but in that price range you'll likely be looking at 20-year-old vehicles. Lots can go wrong in a couple of decades. Avoid models with known inherent problems and be sure to have a good mechanic inspect any prospect before purchase.
Along with what @chucktobias said, I suggest trying to find one with all the right stuff wrong with it.
You want it to be running well, and well maintained, but things like dents or ugly paint issues can drop the price in your advantage.
Another is some rust that is not structural can be nice also, especially if you can get rid of it after buying it.
When I bought my 125k mile 2008 GX470 5 years ago, it had some rust, and the paint was defective, it would just fall off. I would touch it up for the first two years, then painted it when I had the extra cash, and I dealt with the rust immediately. Cost me 10k, and comparable ones were 17k+.
you could get a pretty nice bicycle. Maybe even E-bike.
