The only way for that to happen is for a review of you to be published, at which point you'll get a profile page.  On that page will be your ID number.

 
There is a chance you could have a review on TER and not even know it.   A way to check for it is to go to the Review section, hit search reviews, and enter a unique identifier for yourself in one of the filters such as your phone or email address.   Then hit enter and see if anything pops up.  Be sure to blank out all the other filters before you do.

 
Upgrading to VIP is mostly about getting to read reviews.   If and when you get a profile, you'll be able to apply for limited VIP status that will let you read your own reviews plus use the private mail (PM) system.  Many gals still pay for the VIP upgrade so that they can read reviews of prospective clients.   An informed escort is a good escort.