Just like the macOS Dock, the macOS menu bar can get overpopulated. There’s 3rd party apps that allow you to hide them but with macOS Sierra there’s also a new-old feature that made it back to the OS that allows you to easily rearrange your menu icons.
All you have to do is hold down CMD and click and drag any icon to reposition it. Works with all the icons in your menu bar except the notification center toggle.
If you want to remove icons from your menu bar, hold down CMD drag the icon off the menu bar ( just like you would remove an icon from your dock, but you hold CMD )
If you want to remove third party apps icons from your menu bar, this is usually done from within the app, in the Settings.