Relax, practice, and spend some time doing visualization. In other words train your mind to be calm. Picture yourself doing well, and by the time you compete you should have already done it in your mind so all you have to do is carry it through!
Oh and good luck and get the nerves out now and you'll do fine!
I have a muay thai/kickboxing tournament this weekend. Im pretty nervous and need some tips to calm down.
Its in Iowa and takes about 8 hours to get there. I feel different about it every day but sometimes its sad, excited, or just really nervous. I need hell calming down and keeping control of those emotions.