You can add, remove and rearrange basically all of them.
The thing to understand is that while the menus on the left side of the bar are pretty permanent, the status menus on the right side are infinitely more customizable. The icons on the far right of right, which are called status menus, such as Wi-Fi and battery, are also part of the Menu Bar. The Menu Bar is the thing that runs along the top of your Mac’s screen where all the menus - Apple, File, Edit, History and more - are located.
