Samsung M3 portable hard drive and Mac

[GrumpyMumof2]

We have recently bought a macbook air, and a samsung m3 portable hard drive to use as extra storage and back up.

I'm trying to set the samsung drive up for the first time, but despite the "help" manuals, I'm confused and am hoping some of you lovely people can help me

I want to use the drive (1) as a back up for the macbook, probably using time machine and (2) as storage for my music, so I don't have to use up all the space on the macbook (ideally music will not be stored on the macbook, only on the m3 drive)

Question 1: do I need to reformat the drive from NTFS to mac os extended (journaled) to do this?

question 2: do i need to partition the drive so that part of it is for back ups and part of it for music (or other) storage?

thank you!