Gosh, first time booking excitement is incredibly intoxicating but you need to keep a grip on yourself and think clearly.
Do you have any non-latex condoms in case the client can’t use regular ones? I always take my own mouthwash to freshen up on arrival, along with lipstick or a lipgloss, and a pair of more comfortable knickers to wear home - makes so much difference! I never take my wallet, and don’t take my house keys either but I appreciate not everyone can do this. Keep your jewellery minimal and if you take it off when you’re with the client, put it straight in your handbag, not on the side. Also be sure to keep all your things together, no flinging your clothes off with gay abandon. Keep alert and pay attention to entry/exit points and if the door is locked behind you. Also, be sure that if you decide to accept a drink, the bottle is unsealed and opened in your presence. If the bottle is already open or drink poured into a glass, decline, you have no way of knowing if it has been tampered with. I always take a bottle of water with me just in case.
But, that’s all common sense really. What is most important is that you know the client is actually where he claims to be. You must check before leaving. I know I would’t even consider getting ready unless I know the client is in situ.
If the client is staying in a hotel, be sure to ask for a copy of his booking reservation along with his room number. Phone reception and ask to be connected to the room. This is the most straightforward way to ascertain if someone is in the hotel room they claim to be.
Regrettably I cannot advise re. private residences as I would never visit one, particularly a new client. Hopefully someone else can advise on this.
Equally important is that someone knows where you are - you call them on arrival (although a text if fine), and you agree a time that you will call them at to let them know you are ok and have left the client.
Be sure to get the money on arrival. Feel free to check it, you can always excuse yourself to the bathroom if you don’t feel comfortable counting in front of the client.
Remember to enjoy yourself. Keep conversation light but you can talk about anything you want really (expect anything personal, obviously). Have you decided a back story for yourself should the client try to fish for information?
Lastly, if at any point things don’t feel right, leave.
Am sure others will come along and add things as they see fit.