GFE Girl Friend Experience, typically BBBJ, CFS, DFK, DATY, and MSOG.
For the sex part, it's highly unlikely that you'll use anything close to the actual sex time.
GFE means Girlfriend Experience, which means foreplay, hugs, conversations, enjoying each other's company, etc. It can also mean an invaluable learning experience for you.
In standard bookings, having sex is common. Some escorts will include GFE as their standard service. Their standard prices are usually higher than escorts who have GFE as an add-on and not part of it.
What the escort does or doesn't include also comes down to what she feels comfortable offering.
If this is your first time, telling her that you are inexperienced will help you relax and make it easier for you to enjoy yourself, and female escorts tend to have great insight into relationships and intimacy.