Depends, from where? Did you just put some MP3 files on there? Then open/ download samsung music, it'll add the songs to its library and you can press play.
If you're looking for Apple music/spotify/pandora/ etc. You can download those apps from the Google play store and sign into them and play your libraries there.
If you're just looking to listen to the radio, then there are a multitude of internet radio applications on the Google play store and the galaxy store.
If you want to cast music from a TV or laptop to your phone, connect it via Bluetooth, from your desired device, select the phone as output, and press play, usually though, you will need a casting application like chromcast are plexi
