Friday evening traffic is either the worst or close to it. Assumption is you will have cleared immigration, picked up your luggage, and ready to leave airport. Taxis are available on the the ground transportation level which is clearly marked. Another option, suggested by a Forum member is to go to the arrivals level and grab a taxi that is dropping off someone.
You will have time even with Friday traffic, to check in to Tarntawan, maybe have some dinner, check out the neighborhood, all before the clubs open.