When students are new to programming, they don’t know what to expect. Display your screen while programming to model the process of tinkering, reading error messages, making and fixing mistakes, and problem solving within a programming environment. Students likely won’t be able to replicate all of the things you demonstrated, but it can be helpful for them to see what activities programming involves.
Example: "That didn't work like I expected! What could I try next?"
See this and related tips as a Tip Sheet: http://csteachingtips.org/Tips-for-introducing-computing