Going to a GP

I've been told by a few people that I should go and see my GP about anxiety and other things but I don't know. I don't actually know who my GP even is. I don't want my mum to know about it either. The thought of having to talk to someone terrifies me and I don't know if it will even help??. I'm only 15 so I don't know what to do?? Any advice or suggestions welcome?..