So I had a d* appointment .. and I want to know how to get myself checked?

I thought everything was fine then after he mentioned something about his other partners having infections.. and I’m scared now.

I’m 18, and I really don’t want to tell mum. I just want to know what I have to do to go myself? Do I have to bring anything? Should I go to a family doctor? Will they tell my family? How does it work?