You need a motorbike license, not a car licence and there is no such thing as an international driving licence, it’s a permit, and to drive on a non ASEAN licence you need one of those too. As per the previous comment just pay the fine, if/ when it happens.
It matters what passport you hold not where you travel from, but let’s say you hold a British passport then you don’t need a visa for a 30 day stay. And no, you can’t get a visa on arrival if you have a British passport.