Visa agents in Pattaya, will get you a 30 day tourism extension, they will do everything for you, save yourself a headache, just give them ฿4000 and your passport, everything included.
I'm from the UK, your standard car license has motorcycle entitlement to ride Upto a 50cc motorcycle in the UK, or you can do a CBT course, which then allows you to ride Upto a 125cc in the UK, after that it is a full motorcycle test, when you get an IDP from the post office, it will just be stamped with what ever licenses you can present to them, I only have the very basic motorcycle entitlement, but it was easy to converted them into full thai car and motorcycle licenses.
you only need to have motorcycle entitlement, on your home country licence together with an IDP, to obtain full Thai car and motorcycle licenses, you don't need a full motorcycle license from your home country.
my home country car driving license, and IDP has motorcycle entitlement on it, but I don't have a full motorcycle license from my home country, I converted my home car license into full thai car and motorcycle licenses, at the land and transport office, by doing a simple colour blind and reaction test.
you say you want to study, rather than doing an Ed visa, that needs 90 day extensions at the same immigration office, and you would likely need to stay in that location to attend the school, and you need a 12 month rental contract for an Ed visa, also the extra expense, a much better option would be to do the retirement visa, and maybe attend private language classes, or if you want to travel study on-line, there are lots of options to choose from, so don't forget you're laptop 😉
If you intend on doing the extension yourself, at the jomtien immigration office, you will need to file a TM30 within 24 hours of arrival, some people have reported that they have been fined, when they went to the immigration office in jomtien, to do an extension, and there wasn't a TM30 already on file, if want to make it easier for yourself, when you have 7 days or less on your current stamp, ( jomtien won't do it before that) just go to an agent and they will file a TM30, and do the 30 day tourism extension for you, it's usually around ฿4000 everything included.
you just need to have a photo on your phone of your current visa, anyone saying carry your passport around, it's not them that has to deal with it, if it goes missing!! if you live in Thailand and your current visa is due to expire, you would need to return to your home country, to avoid being on overstay, and to get a new passport, at great expense and a lot of messing around you can do without.
people that live in Thailand, don't generally do withdrawals straight from their home country bank, most do a transfer into wise for instance, which in the UK is a local transfer, so it's better to just do that, when you need to move money to Thailand, also set up all your payees with small transactions, because when you come to Thailand and use your banking app, there will be no suspicious transactions because you might get blocked, just use your Thai bank for everyday usage.
I've heard people mention the exchange booths in the Arab district in Bangkok, I believe they are a lot less fussy with the quality of the notes, it's worth a try I suppose if you're in Bangkok, or just ask a fellow Brit that's on his holidays, if he would change it for you, I remember you posting a while back about having some health issues, if you don't mind me asking, how is your health now??