An Excel spreadsheet is essentially a collection of little blocks (CELLS).  You can jump to a new cell by clicking in it, or you can:

• move DOWN a cell by hitting the ENTER key
   
• move to the RIGHT by hitting TAB
   
• use the ARROW keys to move in the indicated direction
   
• Use the scrollbar on the side of your document to move rapidly to different parts of your document.
   
• REMEMBER the UNDO tool on the toolbar.  Use it.