Help with spreadsheets

I have been trying to use Excel and can’t figure out what’s going on. I can navigate the sheet, but can’t seem to get focus to a particular cell. I’m trying to cut and paste some data, and I always end up with data from a cell other than the one I am focused on. I can’t seem to edit cells either.
So, I opened the same spreadsheet in Numbers. Things worked better here, except that the spreadsheet contained hyperlinked email addresses. Whenever I focus on one of these cells, a blank email opens up. I am not activating the cell, just moving to it. Can this be stopped? The preferences panel was rather sparse and didn’t offer any hope.