If you have trouble relaxing or sleeping, there are loads of great music and soundtracks that you can listen to which are claimed to help. Have a look on Youtube, for example, or Spotify.

Also, Moby, one of the best-known DJs in the world, has released 4 hours of relaxing sounds to help you sleep, meditate and generally chill out. They're free to download at https://moby.wetransfer.com/downloads/b313e4df0c71785dd90f803456486b1320... and they total around 4 hours of MP3 files and 260 MB. The download is a single zip file which you simply unzip and load onto your favourite player.