how to move top/main menu, how to make top/main menu fixed

I read the Documentation on menu but it didn’t answer the following:
My “Main Menu” is located in the first big box with text and images on my homepage. I want it to be located in the first small box with logo and title at the top (is this called a logo or header or title box?), above the main box with text and images. How do I move the main menu?

Also, when I scroll down, the menu moves with the page and covers up the other stuff on the page. How do I make it fixed?

To HB: I am not familiar with all the terminology of web development. It would be helpful if there was a graphic labeling the different parts of a webpage and a source where we can look up different terms.

I will send my info via private reply. Thanks.