heyhey, im 15, and i recently participated in another game jam. it was very fun, you dont have to panic. the people were super supportive and awesome, im sure you will enjoy it! Good luck
I have done one game jam before and am like others that have responded 13, I would say the best thing to do is just to not worry to much and not not concentrate on wining but more on having fun and doing a good job in comparison to your ability not others.