What fees are involved in working for a large Real Estate Company like Century 21?

I don’t know much about working for a Real Estate company, and am looking to work at a Century 21 office in California. How does it work when you work at their office, since you are "in business for yourself". Is there a fee to work at their office? When do you pay them? Is it based on when you sell a house or monthly? Would you have to pay for all the "tools" they office, such as website design, etc? Any information is welcomed!