Have to go throught the obvious things:
you selected a cell in a table, right? A selected cell looks like:
you didn't change the font color to the same color as the back ground did you?
Is the Numbers window in focus? That is you clicked something in a Numbers window to bring it to the front?
When you do select a cell do you see what you type in the formula bar?:
when you are done entering your data in a cell do you type an arrow key or return key?
Upon opening numbers I selected the blank template. The result of doing that is that there are not grid lines, column heading or line numbers. I can faintly see an entry in a cell eventhough the color selected is black. The style chosen is basic. I see the formula bar.
I am lost with the following: "Is the Numbers window in focus? That is you clicked something in a Numbers window to bring it to the front"?
I may have changed the front color to the back ground color but do not know how to control that.
Thank you for trying to help