Hi & WELCOME BACK to LQ! I have a few thoughts to offer... 'ForWhatIt'sWorth'
IF you still have the "old MacBook Pro" with Ubu, from 1.1yr ago
http://www.linuxquestions.org/questi...kes-4175571653
it might be interesting to TRY plugging it in there, to do fdisk/lsblk like above (+1 #3).
Yes, backups are -GOOD-! Be careful (even experienced people have accidentally overwritten wrong drive)!
One way ['safe&easy'] to 'fully run' Linux ON-top of OSX is VirtualBox.
This allows you to experiment, while still having a running web-browser, to web-search.
(A 'plug' for web-searching any&all things!)
OSX isn't as '....' as M$/Win10, so -I- wouldn't be in such a hurry to get rid of it
And OSX 'has/is' 'Unix' (I exaggerate): try a *WEB-SEARCH* of:
Update: OSX appears to call it `diskutil list`, per
this 1st result.
ENJOY! Looking forward to hearing how your Linux 'journey' goes! Best wishes always.