Camera Flash Setup Neither Precise Nor Comprehensive What Is The Best Camera Flash To Use For Weddings?

What is the best camera flash to use for weddings? - camera flash setup neither precise nor comprehensive

As with Nikon D80 and 50mm 1.8, 18-200mm Nikkor 5.8. I have a flash, but what I do for a wedding? What kind of flash, it would serve better. It is difficult to install and configure?
I do not want anything too complicated.