the tdac was re introduced in electronic form over a year ago and is an arrival card nothing to do with visa s or permission to enter thailand. Everybody gets a receipt confirming your form has been received no guarantee at all to get an approved entry
you can enter 60 days visa exempt then extend in country 30 days leave thailand and re enter for another 60 days visa exempt but now onky extend to 7 days so total is 157 days
You need to decide where you are going to stay in thailand and then look to see what soft power (i assume you mean muay thai) providers who are registered and provide you with the appropriate approved course and paperwork to support your application. You will need to sign up and pay for the course before you will get the supporting documents to apply for your DTV. There is a forum that deals with DTV on Facebook so I would suggest you look out for it and join
You need to look for a muay thai gym where you want to stay that is accredited by the thai sports authority and are allowed to give you documents that prove you have enrolled on a course and it is accredited. These documents are then used for you application through your home country or country you are currently staying (cannot be inside thailand to apply for a DTV) through the thai e visa online system. The Visa can take up to 14-16 days.
For the TDAC you only need to fill in the information where the * is highlighted all others are not required. So you dont need to fill in an exit flight