Open your normal.dotm file.
How to Open the Normal Template in Any Desktop Version of Word (except Mac 2008)

I suspect that you have been trying to save a different document or template as normal.dotm. You should never do this. Only a normal template created by Word will be fully functional. That template can be modified, but should not ever contain text.
“Blank Document” Is Not Blank by Suzane Barnhill, MVP