Welcome to the seller community, @BurnAppetit! 😊

Once you've created a category, you should be able to go into edit mode and add it to your grid in the Point of Sale app by tapping any + icon, then selecting the appropriate category. For step-by-steps on this, have a look at this section of our Support Center: Set Up Your Item Grid on a Tablet.

If this doesn't clear things up, feel free to reply here or contact our Support Team with more on where things are getting stuck. We'll get it sorted out either way.