This is a Japanese inspired Moon bridge, so called because of the high arc in the deck. Small scale to fit in a zen garden or other miniature scenery. The truss underneath adds some more details, but it will look great without it as well if you want to save yourself some work. Just omit all the 'struts' parts.
Assembly is not too difficult but it does need some explanation, so I've added some instructions as well as an overview of the parts.
As for printing, the parts don't need any support, but all the struts have to be cleaned from seams in order to fit together.