In rural Isaan they speak a Laos flavored version of the Thai language.
You will find the majority (99%+) of the rural villagers do NOT speak English.
As a foreigner, you might be the first one they have ever seen or interacted with in person.
To get started adapting to life in rural Isaan, you need to learn words as you go.
You should start off learning things that you will use every day.
Like ordering food the way you like it, coffee, general greetings, how to get gas, directions and other basic phrases you will use each day.
Take one day out of your life and analyze the things that you do, then try to learn the words for those things first.
As an example, if you visit a local coffee stand, you might like your coffee with no sugar.
You should learn how to ask for coffee with no sugar.
Follow this pattern and learn the things you will use each and everyday first.
Before long you will feel good about being able to get things on your own and you will continue to learn new things each day.