Cannot add any widgets to apps in personal environemnt

I'm working through the beginning of the web developer course but have hit a road block on the first app, the build an app in 2 hours (planets). Going through the video: - but I cannot add a webscreen to the app as I don't have the left-hand pane like in the video. 

How do I add the pane? 

Hi Daniel,

That's an odd looking screen - how did you get the grey background? Anyway, since the toolbar is context sensitive, you first need to select a Screen or Action before it appears.

That said, to add a Web Screen, you use the context menu of a Web Flow: