I looked for the simplest Thai learning video I could find. In all such videos, recognize that the spelling of Thai words in English can vary. Soooo just as in learning Morse Code, learn how it sounds, NOT how it is spelled. Remember, for the Thai person, they learned to spell it with their own Thai script, which we don't know. Wellll they might not know our English script either! If you ask them how a word is spelled in our language they could easily NOT be able to answer you. So see whether you can learn to duplicate the sound they are making. Here's a video to teach FIVE words. I don't think #3 or #5 are essential at all. I never learned either one of them. The others would be good to learn and she also shows you how to do a proper Wai, a bow of the head with the hands held together. Being polite is fundamental in communicating with Thai people. Check it out!
In traveling with Supattra, I never had to rely on my ability to say any of these words! She took care of everything for me. But somewhere along the way, I learned to how to do a Wai and to smile a lot. That took care of pretty much everything. It will work for you too.