Advice on scheduling a doctor’s appointment without getting nervous?

I need to see a new doctor. I’ve been without a primary care physician for over a year and a half to two years now and I can’t keep putting it off. My only worry is… I don’t know how to schedule an appointment. My mom does it all for me even though I’m an adult because it can get debilitating, but I really want to be able to do this.

What do I say/ask for? I just need to schedule an appointment. I don’t know how to see a specific doctor but that’s what I’d like ideally.