I've seen several provider ads online. When I email for info they direct me to a web site where they want me to sign up (usually $1-$30), after which I will get a contact number. They say this is for the safety of both and to prove neither one is a cop. I'm fairly new to this so I haven't done it yet. Is this a legit practice among providers or am I being scammed?

in the right places - forget CL and backpage and etc and search for providers right here on TER, using the review system and / or your regional board.

Wherever you shop, make sure the lady has reviews, and they are written by creditable hobbyist. That means the hobbyist have written numerous reviews of well known provider. You will need the TER VIP membership, it's well worth it. Good luck!

you will begin to get large charges to your credit card, and you'll damn near have to close your account to make them stop. If you're going to sign up for anything, sign up on one of the reputable verification sites like Date-Check or Preferred411. Between them and TER, it's all you'll ever need.

rs2k
date-check
preferred411

With those sites the fee is usually closer to $70, but they can be useful.  You get screened once by the site, and then ladies that are members just check you out there without you having to get screened by each lady you want to see.
You can also get free membership usually if you can be verified by ladies that are members.

In those cases it is legit.

Anywhere else that asks for membership fees just so you can access the lady's contact information I would suggest you stay the hell away from.