Font change and menu position

Hello, could you please give me a hint on how to achieve the following:

  1. How can I change the font style of the Heading? I noticed that someone had asked the same, but the CSS code provided didn’t work for me.

  2. Is there a way to change the menu position? (below the header and not above it)

Thanks a lot in advance!

I would like to know that as well 2. , if there is a way to position the menu below header.