Martial art school in Bangkok

I'll tell you what you really need to know about martial arts lessons - the lessons are only as good as two things:

The instructor
You

If the instructor is out for the cash rather than the art, move on.
If you don't have an indomitable spirit, take up sewing classes.

My first master was the best I've ever met anywhere, and that immediately reflected in the training and the students. Students without the ability to take the training were lost into the dustbin of failure, not because they were kicked out, more because they wimped out.

Almost forgot - you need to be patient. Nothing at all happens after the first session except pulled muscles and a lot of aches and pains, and the second session, and so on for quite a while.
A year or two in and you'll realise you've changed  - You have no idea what I'm talking about, and won't do until you experience it for yourself. The changes are physical, but are also in your state of mind.

That's a really useful insight Fred, I really appreciate it. I definitely will put that in mind.
Although I am appreciating my own willingness to take step forward, even just by asking information about the martial art school, did some research about it instead of just let that thought sitting there somewhere inside my head.