Linux. What directories do i need to copy over for migration?

[Rodgear]

Was running my server off an old laptop. Will now be running it off a raspberryPi 4. I have some rather crappy internet here in "the sticks" and would rather not have to download all the posters and the like for all the movies and tv shows etc. again and also not having to setup any of the custom collections again would be nice. 

So, what directories do I need to copy over to the new server? Both are running variants of debian. Media libraries are on their own dedicated external drive.

Thanks in advance.