Navbars are typically used across the top of your web pages, to allow your visitors to navigate around your website.
When adding Navbars, I would generally only have a maximum of around 6 or 7 top level links to keep your navigation from looking too busy. So, if needed, each top level section can have dropdown sub-menus to navigate to pages related to each section.
Quick tip: If you decide that you want your navbar fixed at the top (as I did for this website), so it's visable when scrolling, just add fixed-top class to the nav element (<nav class="navbar fixed-top ), then be sure to add to your css body padding-top: 65px; which will prevent any of your content from being hidden at the top when you fix your navbar.