My camera lens is making a weird noise and won't focus

I have a nikon D50.it's a little old but works amazingly well! Today i went to take some pictures (in automatic focus) and the lens made a weird noise. It was a scratching or screeching noise. And it wouldn't focus. The lens works fine if it is in manual. But I'm worried about the lens. I think one of my friends messed with it while i wasn't looking and broke something?
is there anything inside of the lens that could have broken to make a weird scratching noise? Or could it just be dirt?
I just don't understand how it makes that noise in automatic but it doesn't make a sound in manual.
does anybody know what i should do?

It is possible that some grit, or sand has got into the mechanism, although I would have thought it would still make a noise in manual.

Try using a blower brush to see if it will free up.

Sounds like a gear broke or it just wore out. It's easy to do when you try to
manually focus and the auto-manual switch is in the auto position. When
you set it to manual focus it disengages the focusing mechanism, that's why
you don't hear any noise while focusing. If it's a kit lens it's not worth repairing.
You can buy a mint one in the $100 range.

facing the same issue actually… N your friend has nothing to do with lens buddy… I was taking pics at this moment and in the next moment camera got this issue