I had a folder on the sidebar in files, then I dragged it to my desktop because I wanted it to be on my desktop instead. this would've been the only folder there but its gone. I tried to search in spotlight but it doesn't show. restarted my Mac too. its just gone, not in trash or anything.
I think you are misunderstanding how the sidebar works.
What you have in the sidebar is like an alias linking to the folder location.
By dragging it from the sidebar you effectively removed it JUST from the sidebar - the folder continues to exist wherever it was located. So where was it?
If you don't know, you can search for it by name.
I had a folder on the sidebar in files, then I dragged it to my desktop
Drag from . . . iPhone?
Use iCloud Drive, see this Apple articles below:
Set up iCloud Drive -> Set up iCloud Drive - Apple Support
Set up iCloud Drive on all your devices -> Set up iCloud Drive on all your devices – Apple Support (UK)
Access and manage your files in iCloud Drive -> Access and manage your files in iCloud Drive - Apple Support
Transfer files between iPhone and your computer
Intro to transferring files between your iPhone and computer - Apple Support (BN)
Share files and folders in iCloud Drive on iPhone
Share files and folders in iCloud Drive on iPhone – Apple Support (UK)
folder disappeared on Mac
