On the music playing face, tap on the hamburger in the lower left corner and that will bring up the shuffle and repeat options. As far as I know, it’s temporary and you will have to tell it to shuffle each and every time. At least, I haven't figured out how to get it to shuffle by default.
Edit: the music playing screen doesn't offer the hamburger in the Now Playing app, it can only accessed in the actual Music app. It's a hassle but you will need to go to the music app and set it to shuffle there.🙁