I recently installed Linux mint ane was unpleasantly surprised that it is virtually impossible on every desktop environment, as opposed to Ubuntu on which it required very little.
What you want is KDE
Second for KDE. Add a default panel to a screen and boom! You got what you want. Additionally, the DE is endlessly customizable.
KDE can display one taskbar on all displays? If so I would like to know how
Not technically, but you can configure both task bars to display the same things