Moving from Excel 2003 to Excel 2016 (or ( Excel 2007, Excel 2010 or Excel 2013 ) can be fraught with difficulty if not done correctly.
Where to find menu-to-ribbon reference guides, training, and other useful resources for Excel 2013 / Excel 2016 ?
Where to find things you might be looking for, such as the Tools | Options dialog box ?
How to customize the Excel 2013 / Excel 2106 ribbon and Quick Access Toolbar ?
How to exchange files with people who don’t yet have Excel 2013 or Excel 2016?
How to enable Solver or other Excel add-ins ?
Where to find commands for working with macros, form controls, and other advanced features ?
There can be a lot of incompatibilities and teething troubles with formula from earlier versions like vLookups.
I have a quick, visual introduction to the ribbon and other parts of the Excel 2013 / Excel 2016 interface.