Source control: what files/folders to include

My development environment is Arduino using Sketchbook location. Raspberry Pi RP2040 is the controller.
The Sketchbook location holds the source files (.ino and .h), and also the libraries folder.
I want to put the whole workspace including source files and also libraries under version control.
However the number of files and folders are quite high, so I want only to put all necessary files and folders under version control.
Which can I delete without problems?