There is no simple built-in command to center a window on a Mac. But you can use other techniques. Learn how to combine two window movements to center a window, or use scripted Shortcuts, or a third party app.
If you ever lose your Apple ID account password, you can recover it using one of three methods Apple provides. By default you can use their recovery service which could take a lot of time. But you can set a Recovery Contact to let a trusted person help you recover your account, or you can set a Recovery Key as the ultimate secure method of recovering your account.
You can use the Terminal to list files and folders, restrict the lists to only large files and folders, and also just show the ones that use the most space.