I have installed LN for Live and opened the Tutorial ALS file.
I have selected the scene I want to work on but I can't figure out how to get the LN Start screen to show.
Liquid Notes for Live is installed as a separate application that is started outside of Ableton Live. You can find the application in your applications folder on Mac and in the task bar in Windows.
Once you have launched the application, and assigned the LN bridge and LN track you should be ready to go. Here is a video that shows how to get started connecting Liquid Notes for Live and Ableton Live - http://www.youtube.com/watch?v=zSU5vD1TmD8&list=UUy5SKLdfP3Z_Sus27ieZzuQ
Let us know if this solves this issue for you!
All the best,