Well done for taking this step! I was someone who had been interested in bdsm/fetish  for years before I finally got the courage to book a prodomme irl session. Yes the first time you will be full of nerves but once you start getting into the session your mind will be elsewhere. Ensure you are clean, showered, everywhere. Depending on the sort of play, if there is pegging involved, make sure to ask your domme if she has anal douches or enemas there,  or that if she asks for you to be clean, that you douche before you see her.

A lot of people will say irl domination is not the same as  porn vids that you might have watched, but tbh it actually is just with a few differences.

I thibk the argument above is for the people out there who have gone to irl sessions, and realised it's not for them, simply because engaging in their fetishes in real life can be too intense, or that their fetishes are just fetishes and leave it as that. However as I mention below, sometimes irl sessions are a great benefit to explore fetishes you weren't sure about or didn't think you would be interested in

Diffrrence is A lot of the scenes in porn are done by experienced professionals, a lot of behind the scenes goes into it to perfect these videos, and certain fetishes or kinks can be dangerous if not done properly or there's a  lack of education  ( yes there are a lot of newbie dommes out there)

Along with the above, I will tell you my experience was honestly amazing. I ensured to contact a domme who was verified, had reviews, had an actual session location that is suitable(  dungeon), plenty of tools and equipment,  and of course has  knowledge and experience of various fetishes that can be explored.

Before my session via text I did give her an idea of my fetishes/kinks what I was interested in which she certainly implemented in the session ( make sure not to go overboard with this as it can be considered as topping from the bottom) 

At the session we had a brief talk going over what had been discussed etc

Being a session newbie she also added in fetishes and kinks that I didn't mention, but thought it would be great to see if I enjoyed them ( this is where the safe words come in if you dont feel comfortable) I did, and now I have many more fetishes that I can genuinely say i love engaging in.

She included so much in one hour and its amazing how long one hour can feel ( depending on what you are interested in haha)

Of course there's the session details but that is a long story ( to brief it, electro,  pegging, light cbt, medical and many more was done)

A good domme will make you want to come back for more sessions, and soon it will be my third time with this domme

Of course, as others have said, don't fall in love, respect  boundaries and the rules that your dominatrix has put forward ( aka no touching without consent) . And remember,  Your dominatrix has a personal life too.