When you create a project, Rolla generates the scenes and shot suggestions for each scene automatically. This takes the guess work out of how to capture the scene, making it easy to capture each shot.
If you have more to capture and want to add more shots to your scene, first make sure you have completed the required shot suggestions for the scene (you will see the green check mark on the scene name). Then:
Tap the plus button to bring up the shot type menu
select the shot you want to add to your scene
Hit the "Add" button at the bottom to add it to your scene