There's a wide variety of treatment providers to choose from. Psychologist, Licensed Professional Counselor, Licensed Clinical Social Worker, etc, etc. And with every individual counselor there are unique approachments about how to handle certain issues. Get a room full of therapists together ( God forbid

) about the same problem, and there will be a dozen ways to approach treatment about it.
Along with treatment approach is just personality of the person. There's a chemistry that I think needs to be found at times for therapeutic work to take place (not all agree with this). Some use a lot of humor, which for me is a must. Some couldn't crack a smile if I paid them to. All business all the time, type. Some are warm and gentle, where some are more confrontive and skills based.
Just remember that you are seeking a service, and have the right to move on to someone else if you don't feel a connection within the first few sessions.
What to say: Typically they ask "What brought you in today?" I usually stress
today. Why today and not 3 months ago, etc? What's happening that encouraged you to reach out for services? What do you want from treatment (goals)?
I hope the appointment goes well. I do hope you can follow up and let us know how it goes.