Apple Music because I live in the Apple ecosystem and have been in iTunes since the beginning. I tried out Spotify with each redesign. I did not like their interfaces at all. The only thing I found that is better in Spotify (for my needs) is they have way better and more user-generated playlists. That's one thing I miss in Apple Music, but there are apps that will allow you to copy a playlist across services.
It’s super easy to get installed. I recommend a user-friendly system like Mint to start off. I have it installed on a 2015 MBP. This isn’t the exact tutorial that I followed, but close to it.