How to get a ransparent Nav Menu located at bottom of home screen

Hey guys, not sure if this is capable with this theme but if it is I’d really appreciate some guidance on how to incorporate it.

I’d like to have the nav menu be transparent and located at the bottom of the home screen when you first visit my website, and as you scroll down I want it to have a white background and scroll up to the top of the window and stays put at the top as you continue scrolling down

Any ideas or suggestions?

Thanks ahead of time for any help

Colin J