Use the arrow keys or WAD to move up, right, and left. Avoid the spikes and lava. Spikes are black, and lava is light red. Anything else is safe. Some blocks which are different colors are made of caramel or quicksand, and if you stand on them too long. you can fall through them FAST and probably land in a pit where you must restart to get out, or lava, where you die and go to the beginning of the platform. Lava is much, much safer than pits, as you get to keep your level when you die.
Go and check out xamuil2, as he is where I learned everything necessary. Very helpful. Also, go to his channel on youtube HERE: https://www.youtube.com/channel/UC_vPY9sbi5M5hxTbJUAsa8g Half credit to him. If you heart and fav this, go and check him out too.