Hello and where to find DOS disks?

Hopefully this is OK to post here - let me know if not!
I have an old “portable” PC from the mid 80s - a Sharp PC-7000 which has been sitting in a cupboard for a few decades. It doesn’t have an internal disk, only two 5 1/4" floppy drives. When you turn in on it starts up, but the old floppy disks I have are unreadable.
Is there still somewhere where I could get a formatted floppy with DOS on it?
I’d like to try getting it up and running…