What do you want to experience?
BDSM covers a wide variety of activities, if you are a beginner best tread carefully. Fantasy and reality are not the same thing, be careful when asking what you want from a session. Most reputable Pro Dommes will ease you in gently and understand that you are a newbie to the scene.
I would endorse what ulstersubbie says, make sure you have an idea of what you want to try and your limits. A Pro Domme will discuss these with you before the session and will also make allowance for the fact that you are new to the "scene".
Others may disagree, but I would say that whilst there are very few Pro Dommes to be found on Adultwork although there are quite a few escorts that offer a BDSM or Domination service. Both can offer a satisfying experience but the key to achieving it is communication. in this instance as a first timer I would tend to look for a Pro Domme and once you have decided if it's for youy and what floats your boat then look further afield.
Be aware that it's not the equipment, racks, suspension frames, cages that make the session (although that may be what turns you on) but the interaction. I have had excellent sessions that relied on no more than some cord, a blindfold and a "few common household items". Oh and a fiendish imagination

Some of the Pro Domme websites are a bit off putting at first glance, but it is worth discussing things with them. Stress that you are new to it and want to learn.
You don't say where you are, but here are a few PD possibilities:
External Link/Members OnlyExternal Link/Members OnlyExternal Link/Members OnlyThey won't bite - well not unless you ask them to.
You may also like to have a look on Fetlife, it's a sort of Facebook for the kinky

HTH
Senior Citizen Punter