Endocrinologist

Today I had an appointment to discuss treatment for all my PCOS symptoms. Mainly my missing period. Blood work levels all came back great except testosterone, of course. I was referred to an endocrinologist 3 hours away from me. I’ve never been to one and having anxiety over it. Does anyone know what I should be expecting out of this appointment because I don’t even know what an endocrinologist does! I’m very nervous.