For first time users, it may a little daunting/confusing when they first login to the website vault and see an empty vault that simply says, “Add Item” and not much else. And I’m sure you have the stats on this, but the easiest way to start adding items to a vault is to install a browser addon, visit that site and login, and then get prompted to “save” that login.
So, with that in mind, I suggest adding this logic to the website vault:
IF no vault items THEN display 'Bitwarden Browser Extension - Getting Started' youtube video* and any other relevant 'getting started' links/info.
*Bitwarden Browser Extension - Getting Started - YouTube
The “Getting Started” section of the Help page mostly covers how to import logins from other sites. So, perhaps those would be good to display on an empty vault. But I also think it would be good to add some additional info related to adding new items. Perhaps you could display the list of apps you have (the same list that’s on the home page).