i cant figure this step out!
theres not really options on this step.
I'm assuming you are referring to Step 1c in the Map Creation Process. You've already chosen your Source Type (Google Spreadsheet) in Step 1a and the specific SpreadSheet in Step 1b.
Within a SpreadSheet, you can have multiple "tabs" or "worksheets" that contain data. MapAList needs to know which worksheet to look at within your Google spreadsheet. When you create a new Google SpreadSheet it contains only 1 worksheet (called Sheet 1). You can add and/or rename sheets as you see fit (just like you might do in MS Excel).