Being in the Kitchen for the first time might be a bit confusing, but these tips will help you get started:

 🍎  To make items on your Board, you need to tap on Generators. Generators are items with a lightning bolt on them.

 🍎 You can merge items (such as Bags of Flour) to level up basic food and drink items to more advanced ones.

 🍎  To clear Covered Tiles, you need to merge an item next to them.

🍎  To unlock Locked Tiles, you need to merge the stuck item with another item of the same kind and level.

🍎 Bubbles will sometimes appear when you merge items. You can unlock the bubble with gems to get that item, or let them pop which will give you a Coin.