Talk to him about it and set some limits with him.

Planning is paramont to making a relationship work especially a bdsm one.

Comunitcation is key. Also be safe first, kinky second.

Do any of your friends know you are dating him?

If not make sure at least one does, and arrange a contact number you will call to check in with him/her to make sure you are safe etc, just in case.

It sounds scary but you never know, I found out the hard way myself once and allmost wouldnt be here today if i wasnt extremely lucky.

Outside of all that you need to decide how far things will go and establish some limits, trusting him is something he needs to earn with "actions" over time.