You have a few options at your age. An Ed visa is a possibility. You can also just travel around using tourist visas and explore the area around SE Asia so that you know for certain that Thailand is the spot. I recommend that you open a Thai bank account when you arrive so that you have the option of slowly dumping in "spare change" into that account and build it up. That is what I did and am currently doing. I was on a retirement visa but not yet ready to fully retire, but I do just that (stashing a little cash) and when I return back I'll have plenty of funds to begin the next chapter.
*FYI I do work for a company and earn a reliable income, and they will allow me to live wherever. I doubt I will use the Thailand version of a nomad visa while there.
I find it interesting and amusing that a NOMAD visa for Thailand wants you to NOT be a nomad 555 Seriously!
Nomads usually move around, travel, visit other countries. Thailand wants them to park themselves in Thailand and bring a suitcase full of verified income and documents.
It is far easier to actually be a tourist nomad in Thailand. Come in, stay as long as you can, go somewhere else, come back some other time.
For me it's just insane. The cost for some hotel quarantines were as much as I spent on rent for an entire YEAR pre-covid. I miss Thailand a lot, but not enough to spend a year's rent on two+ weeks in a single room.
Thai law. Hotels cannot change Thai laws. They might look the other way....or not. But they dare not broadcast their choices or risk losing their license.