I’m relatively new and had a hard time figuring it all out when I started too.
As with most things in life, it takes patience and resilience to learn. Perhaps more so in this area because it is not publicly accepted.
Most all the suggestions on here are great, would have saved me a lot of time :). I’ll add a few things:
1- decide on your own boundaries. How will you communicate? What are the non-negotiables to you? What’s your budget? Stick to your boundaries, even when you’re tempted to cross them. You’ll regret it if you cross your own boundaries
2- TOB, Tryst, and Slyxa (and others, depending on your area) are all great places to find potential providers, but you want to look beyond that. Most of the legit providers will post in some or all of the boards. Most of the established ones will have their own site for information and booking. Are their messages and photos consistent?
3- Be patient. It’s worth it. My first experience was pretty bad, but I learned a lot from it. I learned even more from my first great experience. You might not get it right the first time, but learn from it and keep going.