You can do it - but have a plan!
First decide which camp you are in. There are two. Either you are coming to Thailand because you want to live here or you are coming to Thailand because you want to teach here. It's important to make this distinction.
What are the the things a teacher should know beforehand?
Everyone always says 'research' is the number one thing for teachers hopping off to a far away teaching nirvana and they would be right, but it isn't until you are deep inside the doors of an international school that you suddenly have a plethora of questions you probably should have asked.