Navigation bar customization questions

Hello! I’ve been able to customize the color of the navigation bar, and right align the text on it. However, there are a few things I haven’t been able to figure out.

How can I make the bar shorter, so it doesn’t take up so much of the total header space?? I’ve tried identifying the element in css and specifying height, but it hasn’t worked.

How can I make the navigation fonts (Like “Home”, “Shop”) bold font? Again, I’ve tried the CSS editor and have not succeeded.

I am using a plug in containing a row of social icons and links. How can I insert that into the navigation bar??

Many thanks for your help. Betty