The first thing a skydiving school will want to know is if you are in physical condition to do it. You don't have to be a perfect physical specimen, but they will want to be assured that you are not going to have a condition that will impair you during the dive. They will ask you to sign a form that advises them of any conditions. If you want to learn skydive then you can also choose the best skydiving centre in Thailand through various online sources.
Having any kind of medical condition will not necessarily bar you from skydiving, but the school will want to be advised. If it is a serious condition, they may think it is inadvisable for you to dive, but perhaps it is something that they will just watch closely. If they are concerned, and you still want to dive, they may ask you to supply permission from a physician.
Pay attention during the training. The instructor will be very thorough about what you should expect on your jump. The experience of landing on the ground on your back may not be a concept that you are comfortable with, but pay attention to your instructor about how to do the famous tuck and roll, and you will have no problem. If you don't understand what is going to happen when you land, you will be completely surprised and react in an unsafe manner.
Be prepared. Being prepared can be one of the most important aspects of success in a sport. Being prepared with the proper equipment can be one of the safest aspects of a sport. Check all of your equipment before every jump, whether you have done it a hundred times or not.
Your goggles, jumpsuit and helmet need to be in good condition and fit you well. Small things, such as a loose zipper on a jumpsuit, can distract you and cause a problem during a freefall skydive. If you are distracted just at the moment you need to open your parachute or land, this can be very dangerous.