Wales Tickets help?

Can you buy the tickets on match day if so what time do they stop selling them and is the canton full?

yes you can and yes still room in Canton stand, they sell right up until kick off but try to get there much earlier if you can

Judging by the FAW e-ticketing website, the lower Ninian Stand is very close to selling out (still quite a bit of space in the corner between the Canton/Ninian) and there is still a few hundred or so tickets left in the Canton, try and get a ticket asap if you want to sit there.