I have a directory with my files. seafile-data How can I connect it to a new installation?
it is not possible to connect your existing data to a new installation unless you as well got the database.
Without the database you can only export all libraries and upload them to a the new installation.
To do this please have a look at the export function of seaf-fsck -> https://manual.seafile.com/maintain/seafile_fsck.html