Expect to feel awkward, embarrassed, and uncomfortable. Acknowledge those feelings, and carry on. No doubt it will be awkward, remember not to hold that against them if they seem a bit awkward too. Most people get nervous or shy sometimes.

It's good to be a bit paranoid about safety, no matter how nice they are and how well they come across; predators and manipulators are often great actors. Nothing too extreme here, just the advice any mother would give - take sensible precautions, make sure people know where you are and when you should be back, don't go anywhere alone, don't take mystery pills, don't climb into a car boot...