How do I make Excel cursor work right?

[Banker Bill]

Once I click the cursor in an Excel cell, it will not move to a different
cell, it moves as if I am dragging it, highlighting all the cells as it
moves. Also, I cannot use any of the top row of tools, etc., including exit.
Same problem with touchpad or mouse. Tried pressing f8 to no avail.

[keithl816]

Try pressing F8

Oops should have read the rest sorry.