I've done some research and would love if someone could confirm my understanding. I want to travel to Thailand from Vietnam on an American passport. I see that I have the option of visa exempt entry if I have a return flight booked, 75 days after entry, probably back to Vietnam. So that means I don't have to apply for a visa online, I just have to arrive in Thailand with the flight information and my passport. Then I can go to a Thai embassy to apply for a 30 day extension. Do I have this right?