How Can I make the menu float? i.e. always stay when scrolling

This stackoverflow thread should answer your question:
It even has example on jsfiddle.

You don’t really want it to float. You want it to be fixed on top.

Oh! How do I do this?

Hi
I tried all of these in custom CSS and none worked.
Any suggestions?

Hi, you mean like this one?
[link removed- advertising your own site or services is not allowed here]

Is that the menu you want?

Okay, I updated CSS and it worked, but now the header is hidden behind the site content. I need it to always be in front with a semi-transparent background so it can be seen at all times.
Is this possible?

Yes that is possible, did you checked out the video?

you need to add to the css rule z-index: 9999;