Take a thai driving license, you could have problems in case of accident with international driving license. It costs less than 5 euros and it is super easy get it. You need only certificate of residence that you can have after you'll have filled the tm30 ( the one online isn't enough, you need to go to immigration to get the paper)
Make a private insurance, not only the government insurance, it costs
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k for year, but in the worst scenario, you will be always safe, which is the most important thing! Enjoy your trip, and take care!