my Mac Air desktop got erased somehow

If you don't have a backup of your files, it may be challenging to recover them. However, you can try the following steps:

1. Check your iCloud account: If you have enabled iCloud Drive on your Mac, you may be able to recover some of your files from there.

2. Check the Trash: If you deleted your files recently, they may still be in the Trash folder. Open the Trash folder and check if your files are there. If you find them, simply drag them back to the desktop or the folder you want to restore them to.

3. Use Time Machine: If you have enabled Time Machine on your Mac, you can use it to restore your files. Connect your Time Machine backup drive to your Mac, and follow the instructions to restore your files.

4. Use Data Recovery Software: If you don't have a backup or Time Machine, you can use data recovery software like Stellar Data Recovery or Disk Drill to scan your Mac's hard drive and recover your files. These software tools are designed to recover lost, deleted or formatted files, and allows you to retrieve some or all of your lost data.

It's important to note that data recovery is not always successful, especially if the files have been overwritten or if the hard drive has been physically damaged. Therefore, it's always a good idea to have a backup of your important files to avoid losing them in the event of a hardware failure or other issue.

If you are logged in as yourself, check your ICloud backup settings. If you are backing up your Desktop, Documents, and Downloads folders to iCloud you won't see those files in the regular desktop. Only if you keep files on your Mac versions of those folders will you see your desktop

Make sure you aren't logged in Guest.