I recently installed QGIS 2.18 'Las Palmas' on my Ubuntu system. I have located the "plugin toolbar" but can't seem to find the actual plugins button.
In this plugins toolbar, the only button present seems to be the python console.
I believe I installed everything properly but I suppose I may have missed some download.
This should be normal in a fresh install.
The menu option plugins > manage and install plugins will let you add plugins. I don't think there's a toolbar button for that.
Bear in mind that not all plugins install an icon to the plugins toolbar - they may appear elsewhere.
Generally, the newer plugins tend to have their own toolbar.
After a while it's easy to get a lot of toolbar clutter. Right-click on some empty space on any toolbar and you'll get a menu which lets you see which toolbars are enabled and turn them on or off.
