First time in a hostel

I am heading out to London and Wales next week. I am staying in a hostel for the first time and am going to be alone in London. I am staying with friends in Wales. I travel alone lots but this is the first time without joining a group tour and now I am getting nervous. Does anyone here have advice to calm me down. And convince myself the hostel is going to be fine and I am not going to regret staying in one.