How can I free up storage on my MacBook Air? My MacBook Air is out of storage but I can't figure out how to free up storage. I've tried deleting videos and photos but this doesn't change anything. I've also tried deleting videos off iMovie but thus also doesn't help. I'm quite stuck, and would really appreciate any suggestions!
Have a look in storage manager, Open spotlight (cmd + space) and type sm then enter. It will show you what's taking the most space and you can delete items there.

In High Sierra it looks like this...