I don't remember exactly how I got all signed up.
I went online and googled "credit reporting". I picked "freecreditreport.com", and went through their process. I do remember being uncomfortable with the process, but figured I had to give them some info to check my credit, just like we do when we pull a mortgage credit. I don't remember authorizing $12.95 a month for their "free" services.
I think the most important things you can do to protect yourself are watch you CC bills faithfully - look them over well each month, know what day they come and check on them if they are a day late; also, make sure your mailbox locks, and control the number of CCs you carry. We used to have the regular "rural mailbox", and we weren't doing these things. We got a dunning notice from a CC company for missed payment, triggered by the fact that we hadn't gotten the bill because it was stolen from the mailbox. The perps had charged a few things on the card, which was made whole by the company, but we still had the late charges and increased interest rate for being late. We have so many cards (well, not really, but more than we wish to keep track of) that we usually leave them locked up at home, only carrying one or two. If you always carry only the one CC, you will know much more quickly if something happens, and if you lose your wallet/purse, then only one card goes missing.