Hello,
If by “home screen” you mean the Windows 11 desktop, save the image permanently in your Pictures folder first so it is not moved or deleted.
Then right-click the desktop > Personalize > Background. Set “Personalize your background” to Picture, select your image, and under “Choose a fit for your desktop image” select Fill to make it cover the whole screen.
To keep the same image permanently, make sure the background is set to Picture, not Windows Spotlight or Slideshow.
Microsoft instructions: https://support.microsoft.com/en-us/windows/change-the-desktop-background-in-windows-4a33c533-b71e-447e-b021-a27df2678938