How can I fix these scratches?

If the scratches are through the paint all you can do is repaint. Some of them might buff out. See a car detailer.

Looks like they're down to the metal in some spots. Best to have a body shop look at it. I'm thinking around $500. In the meantime put some clear nail polish on them so they won't start to rust. Hope that helps! Jim

Watch this video it's from ChriFix a famous YouTuber that does all kinds of repairs, a real professional what can look like a expensive job or project he makes it in a cheap way and ends up looking amazing here is the link to his video. (( https://m.youtube.com/watch? v=Zl_iSYYGBiY&t=1449s ))