I'm quite a newbie in coding/building.
I did a dashboard thanks to an Excel plugged on PowerBI, but I don't find it really robust and I'd like to MetaBase.
Anyway, I don't know what kind of free/opensource DB I can plug on Metabase.
@nikaw Postgres, MariaDB, MySQL, SQLite, ... are open source databases, but again, I think you're looking for the wrong tool. If you are looking for help to setup one of those databases, then you should search for a forum specific to one of those databases.