plug it in with the usb cord provided. if you are wanting to put music on microsd card then click connect as mass storage. If you want on actual phone then click media device. then you have to manually select your music and drag it to your phones music folder or sd card.
Once you've loaded Google Drive on your machine, and it completes its sync, your music will appear on your mobile device once it is logged into the same Google account as long as you've included your music files in the sync.
One thing I notice with this is if you buy music from Google or Amazon it by default downloads to internal memory. There is no way to automatically download to external SD card