By default, Odoo considers that your delivery is composed of one package. But you can easily ship your deliveries with more than one package. It is fully integrated with the third-party shippers.
To configure the use of packages, go to the menu Inventory --> Configuration --> Settings and tick Delivery Packages
Click on Save when you are done.
The delivery created from the sale order will take the shipping information from it.
From here, you can split your delivery into multiple packages.
Choose the quantity you want to put in the first pack in the Done column, then click on the link Put in Pack.
It will automatically create a pack with the requested quantity.
Do the same steps for the other pieces you want to pack in.
Click on Validate when you are done.