I am trying to create a custom stat block via Studio -> Sheets & Blocks. In the tutorial there's a set of options that come up on the right side of the screen to create a new stat custom stat block. But mine is empty, all I have is the search functionality, which is empty. This may be user-error as I'm new to the dashboard, but could not find a solution. I've tried clearing my browser cache and using different browsers.
Click on studio, then select Sheets & Blocks.
Studio -> Sheets & Blocks
in order to create a sheet you need to have the system assigned to at least one of your worlds.
According to the above screenshot you do not have a RPG system assigned to any of your worlds :)