The tutorial narration and videos (voiced by the wonderful Stephen Fry) makes the first level (actually named "Introduction") beyond easy. Even if this was the first game you ever played, the instructions and guidance are pretty clear, so you really shouldn't need additional help here. The standard platforming actions of running to the right and jumping should pull you through the vast majority of the level.
There is, however, one thing that is particularly unusual about this level. The area immediately after the video tutorial of the Popit Menu and immediately before the end of the level contains a Checkpoint portal (with text above that says: "Introducing:") that is unlikely to see use since there are no hazards in the level. As far as I know, the only way to respawn through it is by choosing the Retry option in the Popit Menu. You only acquire the ability to retry in the next level, so that Checkpoint is seemingly purposeless until you make a little more progress in the game. There are many instances in this game where you have to backtrack to an earlier level if you want to see or acquire everything, but this instance is odd as (if I remember correctly) it seems to only function as a small Easter Egg and nothing else.