First, search the help docs and this forum. Maybe your question has been answered! The debugging steps can help, too. Still stuck? Delete this line and proceed.
This can be a me problem. I can’t find info on being able to use an existing Google “vault”.
If you’re on iOS, vaults can only be in Obsidian’s app folder (either My iPhone > Obsidian or iCloud > Obsidian). You can work around this with the Remotely Save plugin but if I remember right it doesn’t support Google Drive yet.