I keep getting messages that I do not have enough storage on my MacBook air.

A user has no control over “Other” category of storage.

• Other: Contains files that don’t fall into the categories listed here. This category primarily includes files and data used by the system, such as log files, caches, VM files, and other runtime system resources. Also included are temporary files, fonts, app support files, and plug-ins. You can't manage the contents of this category. The contents are managed by macOS, and the category varies in size depending on the current state of your Mac.

       https://support.apple.com/guide/system-information/see-available-storage-space-syspf9b375b9/11.0/mac/11

What a user can do?

   1.  Delete files

       https://support.apple.com/guide/system-information/find-and-delete-files-syspf5a64aa6/11.0/mac/11.0       

  2.  Optimize storage

       Click the “Manage”button. Wait until Green “Completed” button appears.

       https://support.apple.com/guide/system-information/optimize-storage-space-sysp4ee93ca4/11.0/mac/11.0 

 3.  How to free up storage space on your Mac

      Try all steps posted in this article

      https://support.apple.com/en-us/HT206996