I have over 1000 albums and I was wondering if there is a way to paginate them in the backend? cause it takes a long time to load them all

You maybe should organize them in subalbums for better overview anyway.

It is not possible to paginate them because that also would kill the drag and drop sorting.

You can also change so that no thumbnails are shown on the album list. This may help the speed of loading.

How to turn off thumbnails in backend?

There is a button above the list.

Admin => albums => on top of the thumbnail list you see a button called:
Show thumbnail stand-in.
This replaces your thumbs with a default folder image.