It's only a file you are transferring onto an SD card so if you are conversant using drag/drop, or more importantly copy/paste commands on a PC then you'll be fine. You can rip with any media ripping software you please, some have favourites such as Exact Audio Copy or dBpoweramp. I'm not conversant with Mac OS so not sure what ripping software is bundled with it.
Doesn't have to be FLAC or WAV files, if it's music for on the go then smaller file size 320kbps mp3 might be sufficient for your needs.
Come back with any questions as I'm sure between us we can get you through this