After selecting an opponent from the My Opponents tab, click on the Scouts tab, then select the "+" button to get started.
First, name the report and select the date of the game. Then, select the Template Type. This controls the set of tiles that you start with on the scouting report. You'll be able to create and save your own templates as you go. Choose from a Blank Template or any Saved Templates you have created.
After creating any report, you can edit the game date in the ScoutBuilder.