GW2 itself has no Controller Support so you’d need 3rd party Software to map it.
Also mapping all necessary functions to a usual Controller afaik is pretty kitten challenging. Let’s go throuh it:
Camera and movement can be done by a 2-Stick mapping, especially with action cam and ground target assist.
Then there are 5 weapon skills, a weapon swap (or drop bundle) button, an interact button, the heal skill, 3 utility skills, the elite skill and up to 5 class specific skills. For simplyfication I’ll assume you play necromancer who only has the deathshroud. That’s still 13 inputs which is more than a controller usually has buttons, so you already need a “Mode-switch” technique via the shoulder and trigger buttons.
You could save yourself the dodge by using directional doubletap.
While this all looks feasible, bear in mind that you sometimes need densely timed actions for decent play, which can prove difficult with such a setup.
Also you still need to emulate a mouse let alone for inventory management.
Tl;dr: Controller Setup may be possible, but very clunky and difficult.
Really only plays well with keyboard and mouse.