Many escorts leave a number on their website. Just contact the number and arrange a time to meet. Don't bother messaging saying you're a virgin and nervous and all this stuff because some don't like being messaged. Contact by phone and perhaps mention it if you have to, but I'd avoid it if I were you.

Also look for rep. The good escorts will have many good reviews. If you see an escort with no rep avoid because although they may well be genuine and just starting a profile, there's also some scams out there. If you see one with many good reviews and the odd negative review that's fine, but of course avoid one that has many negative rep.