If you want to be safest, you’ll spin up a new server, Move a Discourse site to another VPS with rsync (I’d skip the database files), and restore a backup.
I’m pretty sure that you’ll need to PostgreSQL 15 update.
There should be no issues with WP Discourse. You can check Discourse Category Lockdown.
There’s a pretty good chance you can just follow the PG 15 upgrade and everything will be fine, but you asked about “best practices”.