Hi everyone, my education visa expires on December 5th, and on the 13th I am going to Vietnam for a week and then returning back to Bangkok to catch my flight back home. I'm a U.S. citizen. My education coordinator(who is pretty clueless) told me that I could simply leave the country a month before my flight back home so I wouldn't have to worry about extending my visa. Could I get a tourist visa when I return late November, and would I still be able to go to Vietnam and come back with such a visa?

Any help would be greatly appreciated. Please let me know if I need to clarify anything.

You can get a 30 day entry without visa and then get another one when you return from Vietnam. You do not need a visa to enter Thailand as long as you have outbound ticket within 30 days and 10k (baht) or more in funds.