you can't just drag/drop programs, they won;t work if you do that and will mess up windows. If you want to install them on D you need to uninstall them from C and set their location as D when you reinstall them.
You can move library folders like photos, music, documents, movies by doing the below, I will use music as an example
create a folder on D called Music
navigate in file explorer to the library folder for music
right click and choose properties
click the location tab
choose move and select the music folder you made on D drive and choose apply. It will ask to move contents and say Okay provided the address is correct.
define other stuff?
if this is Windows 10 you can also move the onedrive folder which would clean up space as well.