There are a few ways to add cells in Google Sheets. The first way is to select the cell where you want to insert the new cell, and then click on the "Insert" tab and select "Insert Cells." The second way is to select the cell where you want to insert the new cell, and then type in the cell's desired location. The third way is to use the mouse to select the cell you want to copy, and then drag the mouse to the desired location and release the mouse.