Hi Joshua
Before you even think about MLS fees and marketing, you need to get your license. This takes multiple classes. When I got my real estate license, it was 3 classes and about $500. Then you need to take the CA state test which is also pretty expensive. If you pass, you need to get finger printed (more money), and pay BRE, CAR and your local association fees. I pay about $500 yearly. You will also pay an additional ~$500 every 4 years to renew your license. You will need to work under a broker who may have office fees and E and O insurance (each broker operates differently). I pay $152 quarterly for MLS fees. Marketing fees depend on what you want to spend. I pay between $10,000 and $20,000 per year. Once you pay these fees and you close a deal, your broker will take a portion of the sales.
I am not trying to discourage you. I think having your license is a huge benefit. You may even be able to find a broker who will help pay for you to get your license. My first broker reimbursed me for my classes when I started making sales.