If your desktop has changed
If your desktop looks different from the last time you used your Mac, and the Mac has multiple users, another user may be currently logged in, and you may be using that person’s account.
Do any of the following:
Look in the menu bar in the upper-right corner of the screen. If fast user switching is turned on, the name of the current user or a generic icon is displayed there.
Click the fast user switching menu. The current user is identified by a checkmark in the menu. If you’re not the current user, you can use the fast user switching menu to log in. Choose your name, then log in.
For more information, see Switch quickly between users.
If the home folder isn’t yours, choose Apple menu > Log Out, then log in as the correct user.
If you’re logged in as the correct user but the desktop looks different and other users have access to your Mac, it’s possible that another user changed your settings. To protect your Mac from being modified by others, see Set up your Mac to be secure.
Your desktop may also look different if you turned on iCloud Desktop and Documents on this Mac, and then changed the desktop items on iCloud.com or another Mac or iOS device that uses iCloud Drive. For more information, see Store your desktop and documents in iCloud Drive.