There are many types of jobs I can't take because I am not willing to own a car at present. I could not be a farmer, carpenter, general contractor, or any number of professions that require hauling a bunch of stuff around or covering hundreds of miles each day. But I don't look at that as limiting my life, I look at it as being set free from sitting in traffic to basically "break even" with my car-free life.
The way I got started was to find a job I really liked that looked long term. Then i moved to a cheap apartment reasonably close by work and right next to a shopping mall with a grocery, movie theater, and lots of eateries. THEN i ditched the car. When my company moved, I relocated again within a mile of work and a nice supermarket. So if I woke up tomorrow and was a freelance nurse, I would obviously have to tender my resignation after finding a more stationary job. Then move close to that job.
Ditching the car is certainly not for everyone. With enough motivation, and willingness to live in or very near a city, or work from home, it can be figured out. It is certainly not for everyone. And personally, I would have no trouble owning a "work" vehicle that actually brings money INTO my bank account if I liked driving. It's more than just gas money. AAA estimates it costs roughly $8000 per year to own a dependable car. Some spend much more. So I would have to make $8000/yr more to just break even.