I offer two types of shipping, 1-personal pickup, 2-courier. The problem is that products sent by courier cannot be reserved from Saturday or Sunday (the rental start day can be from Mon to Fri) and before and after the rental period they should be blocked for 2 days for the time of delivery by the courier. On the other hand, orders with the possibility of personal collection in shopify can be marked on Saturday and Sunday, and there is no need to block additional days. You can receive the item on the same day if you place your order before 13:00. What is the best solution to design? How to allow customers to choose the delivery method first, then a personalized date picker will appear depending on the choice of delivery method.
Hey @miwaszko , our app Store Pickup + Delivery is able to do just that!
We offer three options on our widget which appears on the cart page - store pickup, local delivery & shipping of which the names can be changed to suit your business.
In your case, if you are only offering 2 options, it could look something like this:
We have the option to enable the date picker for each method and we also have a feature called “Preparation time” which will help you with same-day orders before 13:00. If you’d like to read more about this feature, check it out here: https://support.zapiet.com/en/articles/6279932-cut-off-times-for-local-delivery-store-pickup-and-shipping
Our app comes with a 30-day free trial so I would recommend giving it a go! Should you have any questions, please do not hesitate to reach out 
Klaudia from Zapiet!