If you accidentally followed the instructions to use Multiple Grids - which provides your players with different numbers to root for during each Quarter or Half or game of a series - don't worry! It's a very simple procedure to undo.
Simply navigate to the Grid Setup page within your Contest Settings, scroll down to the table that lists all of your Grids, and click the Remove button next to the grid(s) you want to remove.
Once you are left with just one single Grid, you can rename that single Grid to whatever you want, link a scoreboard, and change the Top and Left labels to whatever you decide.