

Adb is a command line program. To copy your music folder from home on your PC to internal storage on your phone, you would just open a terminal abd type adb push ~/Music /sdcard. Pressing tab will autocomplete folder and file names. For some reason /sdcard on android is actually the internal storage. If you have an SD card, it will be in /storage/card_name, where card_name is the UUID of the partition on the card.
You do have to enable USB debugging on your phone before you can use adb to transfer files though.



Yes,
adb pulltransfers from the phone to the computer.