My cousin and his wife are actors. Both started in local community theater/high school plays and then studied performing arts in college. They made a lot of important contacts through their alumni association, got hooked up with agents, etc. Both have worked on stage, movies, tv, commercials, web series, soaps, etc. They live in NYC and the vast majority of their work is in the city with a few times having to fly to LA. I would consider them professional actors that are making a living doing what they love. She has a fan base from the soap she was on and sometimes pops up in Soap Digest, but they both are pretty much normal people who are actors.
We live about 2.5 hours from NYC. My one friends DS7 and DD3 do commercials. She has a casting agent in NYC and they drive up to NYC several times a month for auditions (more in the summer when school is out). Her kids have been in a few national commercials and her DD in a national print ad. They have been auditoning for 2 years and have each booked 1 commercial and the print add. Its a lot of work/time/money. From my understanding, there really isn't much "acting" skill involved. Its more if your kid fits the "look" the casting director wants and then has the right personality for the spot. Her kids are biracial (spanish/caucasian) and they actually advertised that for both the spots her kids booked. She will be the first to tell you it is mainly luck with commercials....but an agent will be the one to find out about them and set them up. In most cases it would be almost impossible for a regular person to find out. The other thing is that they usually have a pretty quick turn around. She only usually finds out about auditions a day or two in advance. Callbacks are usually right away and then filming withing a week or two. Its not easy.
Hopefully some of this helps you figure out what direction you want to go in.