Clients will approach you, once you’ve set up your profile, by sending you messages. They will ask questions that you will definitely know the answers to; free dates, availability, and other questions that fill in gaps in their knowledge and let them know if you are who they want.
You are going to want to respond to any messages quickly and in full, otherwise the client will have to move on. Clients are on schedules, they can’t waste time waiting for answers.