The shortcut key to edit the selected cell?

- F2 alone: edit the active cell and put the insertion point at the end of its contents. Or, if editing is turned off for the cell, move the insertion point into the formula bar.
If editing a formula, toggle Point mode off or on so you can use arrow keys to create a reference.

- Shift+F2: adds or edits a cell note.

- Ctrl+F2: displays the print preview area on the Print tab in the Backstage view.

Source: Microsoft support