Lol I could write a book about this.
Yes - be polite, presentable, precise. Also be careful. This is true for any class and country. Like all walks in life.
Check reviews about the girl and make sure she's worth your time and money.
And don't be afraid to say clearly what you want and except, or if you feel she's not delivering on her promises. Of course politely.
But also you are bound to have underwhelming or even bad experiences on occasion -- then it might be best to get the fuck out.
I would say get your hands dirty and experience it. Don't overthink it. If you're in a country where it's illegal, expensive or dangerous... consider visiting a country where it's cheap, easy and safe. Germany/Netherlands/Switzerland/Austria and Thailand are maybe the best for newbies. Maybe costa Rica if you're in the USA and speak a few words of Spanish.
Beyond that this is such an open question...
You want to get laid and no fuzz? Then don't talk to the girl more than you need and bang her.
You want to live out fantasies that no one else has let you? Find a girl that can cater to your needs and invest some time in building report and seeing her a few times, maybe give her gifts even.
You want a girlfriend or sugar babe experience? Then communication and setting of expectations is very different.
WhatsApp and texting is the normal MO. But don't underestimate how much a phone call can convey. It's happened to me that I set up a meeting with an escort and we end up talking on the phone over an hour before... When the chemistry is good. This might be totally unnecessary of course if you just want to fuck.
Always be extra clean and fresh with cologne and nice clothes. They notice this more than you think.
Yes be nice, don't be an asshole. Unless of course you find a girl on whom being a just the right kind of an asshole really gets her to want you.
I would always use protection for intercourse. For oral sex you're relatively safe without, but safer with of course.
It's also totally fine to ask if she has been tested for STDs recently, politely. It's normally not a good sign of this question causes any problems. Under regulated circumstances (like in Germany), active sex workers test every 1-2 months. I've never gotten any STDs from sex workers, and I banged hundreds of them.for comparison -- I have gotten chlamydia twice from normal girls. It's pretty common, no issues and just 10 days of antibiotics.
I've dated a few escorts in my life and befriended several. You might not want to have anything to do with them beyond sex -- which of course is totally fine as well.
Out of curiosity, any reason in particular that you never tried? I've contributed to some articles in my home country on prostitution and sex work, covering misconceptions, public opinion, consequences of regulations/illegality etc. I'm from Scandinavia where buying is illegal (though selling is legal) and it's slightly more taboo than in Germany or Spain. Still it's prevalent and common, and many Scandinavians go to countries where it's cheaper and easier -- Denmark, Thailand, Germany, Netherlands.
What are you looking for out there?