I don’t have a link available but I watched a YouTuber who lives in Thailand for many years who filmed an interview he had with an official of the Thai immigration who made this statement that you can extend your initial 180 days at the immigration office for a further 180 days and after that you will have to leave and re-enter Thailand via a border , you will also have to show the letter of the school you are attending, be it Muay Thai , cooking , massage etc etc to prove you are adhering to the criteria of the visa .
I don’t want to burst the bubble but the visa is issued as a 180 day visa for 5 years but each 180 day that you stay you have to prove that you are doing the preferred course or possibly a different course that is within the accepted criteria.
You can’t just obtain the visa and then digress from its proposed use
Your passport will automatically be stamped with a 60 day tourist visa that you can extend for a further 30 days at an official office once you are in Thailand.
Just take your British sterling in £10 , £20 notes to exchange into Thai baht , make sure the notes are in good condition with no writing on otherwise they will not be accepted.
Only drink bottled water and make sure the chicken is well cooked .
Take some over the counter medication with you such as indigestion tablets and painkillers and antihistamines, always apply mosquito repellent everyday to your exposed skin .
Don’t eat spicy food unless you can take it .
Beware of taxi scams and Tuk Tuk scams and last but not least Have a great time