Booking types is where your Booking Categories and Products are stored, these products auto fill in to new events and can be edited in bulk.
The Booking Categories themselves will be created and added to your dashboard by your account manager, you can reach out to them at any time to edit or create new categories.

Different Products will need to be set up in different ways, it's always worth contacting your account manager if you're planning to change the Products you are including in a Booking Category.
When editing a Product you have the choice of whether or not it affects Events where the Product is already in use.