I am not sure if participating is good cause I barely even know how to use Godot and I only know how to do pixel art and I am nervous. 

Just do it, you have nothing to lose and you may surprise yourself. Also the learning process and the feedback is great. 👍🏻

same except I don't know how to use any game engine at all

If you barely know how to use godot, that's even more of an excuse to try the gamejam out! The no. 1 reason for joining game jams is to learn and improve!