I participated for the first time in the previous mini jam and I Would like to recommend to don't expect to achieve high results but also don't demotivate yourself.
You have time to work and even though you might not be as skilled as many other people, being it in art, music, or coding, the objective behind the game jams is to learn, try new things and have fun. Therefore, have fun!!
This experience is awesome and I can say for sure that you are going to love the voting period, where you will not only be able to try others' games and learn a lot from other people and the concepts and ideas behind those but also learn from comments and reviews you will obtain from people playing your game.
Just don't forget as I did in the previous jam that the limitation is something that you should really take into account!
Good luck and hope I will play your game and many others :D