I did it! After weeks of coding I made my first platformer! I am NOT the best at coding and don't know a lot...but here it is. Its extremely laggy and I have no idea what I'm doing wrong, but i'll just stop tweaking it. Also you can only use arrows and not wasd, just because I'm lazy :)
Actually, use turbo mode...it helps. Also from my adjustments, when you press the sign, it pushes you down to the bottom of the world. So just press the flag, and DON'T touch the sign if you've read it already.