First Time Domestic Fly. :d

Hello i am a new member I have some farang friends in bangkok so i join this forum.

I will fly to Udon on Nov. so i will have some time to read topics and stuffs here..

I am Thai and never done domestic flight before.. my trip will be with Air Asia..

I like that it is cheap (even cheaper than a round trip by a coach).

It will be also the first time to go Suvarnabumi airport. What is the best way to get there?

Taxi or the Van from Victory monument? I think about to take the van, but i am not sure where is the van would stop at.

(I am at about Thailand Cultural Center)