I can't see the shuffle icon yo turn it off.

[#1]

when I play a song some random song plays.

[AlejaR]

Hey there,

Thanks for posting in the Community and welcome.

We'd like to confirm, is your account on free service? If yes, keep in mind our free experience on mobile is different: music on-demand is a Premium feature, so it's expected to see the shuffle button like this:

 

It's also expected for the app to add suggested tracks within the same album/playlist. Keep in mind, these recommendations are going to appear, even if you disable features like Autoplay. You can read more about the free experience on mobile here.
 

If your account is on Premium service, you can find the shuffle button at the top of playlists:

You can also find it on the Now Playing view. So, in this case, if perhaps your account is on Premium, and you can locate the shuffle button, would you mind sending us a screenshot of what you're seeing on your side?

It'd be really helpful if you sent us the make/model and OS, along with the Spotify version you're running on the device on which you're noticing these issues.

Keep us in the loop!