If you have been offered a job, shouldnt they assist you in taking care of your visa? Companies have to do some paperwork for you to be able to get a non b, but I heard it is pretty difficult now because of the pandemic and Thailand strict guidelines at the moment (looking like the near future will be strict as well so if u get out it will be hard to come back in unless you are prioritized). You could circumvent and try to get a visa through a language school but you will have to attend classes. Either that or get a volunteer visa. This is only my perspective and experience.

Your options now would probably only be a volunteer or an ED visa. I could be wrong though.