My new MacBook Air storage is almost full

iCloud is primarily a syncing service to sync data between all of your devices and data on iCloud also has a local copy on your devices. You can potentially reduce the local storage by:

1. For Photos, turn on Photos Preferences > iCloud (at top of the Photos Preferences window) > Optimize Mac Storage. See: Set up and use iCloud Photos - Apple Support
2. For iCloud Drive (including the Desktop and Documents option) turn on Apple menu > System Preferences > Apple ID > iCloud (in the sidebar of the System Preferences window) > Optimize Mac Storage (near the bottom right of the window).

Also, if you just bought the MacBook Air and decide that you want one with more storage, be aware that there is a 14 day return period if you purchased it directly from Apple. See: https://www.apple.com/shop/help/returns_refund

Is it a refurbished Mac , as you mentioned just bought it .

In finder > applications if you are an administrator , right click on unknown apps / softwares and move to bin , restart Mac and empty the trash .

Install and uninstall apps from the Internet or disc on Mac - Apple Support

Hi leylanaj! If you don’t have any important things stored on the Mac, then I recommend resetting it to factory defaults.

that may fix it.