Introducing myself

My name is Siripong. I'm a Thai and also my native language is Thai.
I live in Bangkok and work in there as a civil engineer.
I like playing football and badminton but I now have been crazy with playing golf (I think anyone has to love it if they had try it).

Good try with the past perfect, but "if they had tried" refers to what didn't happen in the past. You can use a basic zero conditional (if [simple present], [simple present]) to state a fact.

I'm learning English and I want to improve all of my language skills: entire listening, talking, reading and writing. Especially because Thailand is going to join the AEC in the next few years, then I have to prepare myself for that, that make me be disadvantageous otherwise I would be at a disadvantage if I couldn't communicate in an international language.
So thank you in advance for any help.

Good work!  The phrase you wanted is to be at a disadavantge (or, to be at an advantage).