The very last tab in the app is Your Library.

They tend to be well-curated and long - each one has at least 25 songs. The Genres & Moods section is a way to find playlists made by people on Spotify's team. The tiles at the top are playlists that Spotify thinks you'll enjoy, based on your listening habits. If you want to get lost in a sea of music - or maybe let music find you - go here. That feature isn't as good as Pandora's, but it suffices when you just can't decide on a playlist. You can go for one of the recommended stations, choose a genre, or tap the '+' button at the top to create a station based on a song or artist. Here's Spotify's attempt at giving you a Pandora-style option. After searching, scroll allllll the way to the bottom to see Playlist results. Search for something like 'best rolling stones' to see if anyone in the community has made that playlist. Tap the Search tab, type the song name or artist, and you're set. This is where you go when all you really want to do is play 'Love Yourself' on repeat. You got Spotify because you want to play music.

The tips here work for desktop, but if you're following along, do so with the phone app.

How to download music on spotify