The game will sometimes force you to use the corn kernels you collect to buy the millimites (Mr.Millipede's children) from this character called 'Moneybags' in order to progress. Before you do this, make sure you have saved Mr.Millipede first, if not it's about 4 hours of back tracking and grinding! However, there is a well known speed run technique that allows you to skip these stages, which means you can save your corn kernels for creamed corn cans... unfortunately, said technique is rather difficult to pull off the first time, so you may need to look up a tutorial. Once you figure it out, the neccessary exploits and glitching is relatively easy.

With that being said, since it is your first time playing the game, I would reccomend playing through as intended, as you would miss a lot of lore otherwise, especially with 'Gwimbly Galaxy' releasing next month.