1. Enter Data in a Cell.
a. Select the cell in which you want to enter the data.
b. Type some data and press Enter.
c. If you need to correct what you've entered, please read the next post or type backspace before step b.
2. Delete Data from a Cell.
a. Select the cell of which you want to delete the data.
b. Press Delete.
*Note: Read next post (How to edit a cell?), if you only need to delete some characters, not the whole data of a cell.