Ask this question in your regional board, and do research by looking up provider reviews in your area.  The best help you'll get is what you give yourself.

First off an "escort' is a euphemism for a paid date and a "paid date" is a euphemism for a provider. A "provider" is a recent euphemism for courtesan and "courtesan" is a old world euphemism for an upscale hooker.
 If you wish to learn about the "escort industry" it will require your continuing  patronage of many providers for
their isn't a college or manual by which they universally adhere by.

Please forgive my blunt candor but your question is so hopelessly naive  that it sounds like you're LE (Law Enforcement)