I want to apply for Dtv visa, Soft power muay thai or cooking course.

My question is if the course has to have a minimum lenght to be accepted.

I'm still not sure whether to live in Phuket or Koh Samui, and what would be the exact location in one these 2 islands.

I don't want to pay for a course in one place if then I decide to live in another.

Would Muay Thai be accepted for a 55 years old woman? Obviously I dont want to go on the ring, but would love to get fitter. I regularly go to the gym and I can consider to do something more challenging. I would start from a basic course.

Thank you