Spotify or Apple Music?

First of all it depends on what Phone or computer you own.
If you don't own a iPhone or Mac (etc) don't get apple music. Apple music only has verified artists songs (if I'm correct) meaning only big name people can have music on there.
Spotify is also pretty good. It has a slightly wider variety of music. It has some smaller names on there networks.
If your planning on getting Deezer you probably shouldn't and just get Spotify instead, no hate it's just you will get more for your money with spotify.
For the largest variety of music get SoundCloud GO+. Soundcloud GO+ is super underated. I have both Spotify and SoundCloud GO+ and I use SoundCloud more.
In my personal preference I would get SoundCloud GO+.

To sum up what I just said...

Apple Music: If you don't own a Apple product don't get it. Still nice but has big names only (won't find your friends mixtape)
Spotify: Good service with a pretty wide variety of music.
Deezer: Not horrible but you should probably get Spotify instead
SoundCloud GO+: My personal Favorite with Largest variety of music, includes most genres while the rest don't. (If you like EDM Spotify has some but not a lot).