I would like them in a certain order but it is weird to go around favoriting and unfavoriting them all over again so is there like a drag and drop thing I can do?
Sorry if there was some help section on this I missed.

Actually, that is the only method I know.

Unfaving and then faving again. Since it's rather annoying given it has to be done one by one, I rarely do it.

I don't particularly care about this function myself, but if i wanted to do DnD rearrange, I would:

1. write a program that fetched all the thumbnails of my favorites using the e621 API, and stored a database mapping thumbnail name to post ID. I would automatically prepend a number to the filename corresponding to its index in my favorites, so that the initial order shown in the next step would match the order they were favorited in. Run this program.
2. Use an image viewer program that supports collections, like GQView/geeqie, to create a new collection containing these thumbnails
3. Drag and drop them until I'm happy with their order, then save the collection.
4. Write a second program which loads the database saved in step 1 and the collection saved in step 3, reverse the order of the items in the collection, unfavorite all the items I had favorited (using the API), and then favorite them in the order listed in the collection.

This is off the top of my head, so YMMV.

...Why would you want to rearrange them?

If you want to look up a certain pic, you can just search the tags within your favorites. But if you really wanted to, you could create a set and put them in the order you want.

I agree it would be nice if you could arrange the order of your favorites after the fact. But as far as I know, that's not possible. I was going to suggest creating a set, like SirAntagonist suggested, but when I looked into it more I realised that you can't rearrange the order of posts within a set either. As far as I know, pools are the only places you can rearrange the order of posts in, and those aren't meant to be used this way.

Maybe you should suggest it as a new feature on the Feature Request Thread https://e621.net/forum/show/30573 ? I, for one, would use it now and then. Surely if we can rearrange order in pools, there's a way we could do the same for sets and/or favorites, it seems like. It doesn't hurt to suggest it.