for a first timer here is my advice
1. user a reputable provider, don't take the risk of someone that just looks good but has no reviews.  If you continue with the hobby and get more experience you'll start to know how to tell fakes from the real thing.  The other benefit is you want the first time to be good right?
2. if you want to be a bottom, give yourself an enema the day before and prob another one the next day.  Thinking if you are going to make a mess is not something you want to be thinking about. This is key
3. Unless you've been using toys, you may not want to go with someone who is "well hung"
4. don't be cheap, splurge a little for your first time.
5. if you don't want to worry about STD's do covered everything, but that's your choice on your risk tolerance, no one else can make that decision for you

 
You may want to try Cameron in Chicago, she's cute, a known provider, not latina but whatever.