Not a Mac man myself but I assume browser differences between platforms are minimal, especially the GUI.
What can you see in the browser window, any buttons at all? If so, right click any area of that menu bar and select Customize.
A new window will open. Find both Address and Search and drag them both out of the window onto the browser menu bar.
Does that work?
If not, is the browser window full screen? If so, press F11.
The latest version of FireFox I lost my address and search box. Please assist me.