Go to Items--> Items, now select Add Item in Create page select your parent category in Select Category and add price in Item Price section, add start date time and end date time in respective fields. 

Provide the item name, and its descriptions in Item name, Item Short Description, and Item Description field.

Now choose an image in Choose File category and select the status either Active or Inactive to notify your customers whether the item is available or unavailable and Save the changes.   

You can hide the item from the list using On/Off button and can also delete a particular item using delete button. 

Edit your item anytime you require using edit option.

The items you created here will be added in your website's Our Menu page.