You can create an "own" delivery method with a fixed price.
Go to "Delivery methods" and select "Create". There you can choose "Shipping costs" in the drop-down and Save. Subsequently, this delivery method can be edited and a fixed price can be deposited.
The same applies to the delivery method "pick up".
Important: Please note only that with these delivery methods no more system-side address validation is carried out and you can also must manually take care of the creation of the respective shipping labels.