CSS navigation help

Hello,

I am kind of a word press noob. I have build websites before and I have a good understanding of html/css but now I am going to try to convert a design into a wordpress template for my website. I have done a good deal of research. So where I am stuck is here.
I need to build a fancy css nav menu. Is this something I can setup so that word press can dynamicly add additional topics to? Or do I have to go somewhat bare bones to do this? Can anyone send me some links to info or tutorials on this topic please?
I’m not sure if there has been a previous post on the topic. I just signed up minutes ago. I really appreciate any help.

Thanks john.