you’ll usually sign up to an agency and the agency handle everything. The punters will also sign up, see what’s available and pick what they like. Whoever runs the agency will then deal with the business side of things, so the T&Cs, money etc. the punter will pay the agency, a % stays with them and the girl will get the rest, she will be told when the meeting with happen, how she should dress and act etc
My boyfriend did it years ago, his was a no sex contract so he was purely used for business events etc. he found an agency he liked, signed up! They created his profile and then when a woman needed him, they would make the arrangements via the agency, he would then be contacted with all the details of where he was needed