Thank you in advance for any direction you can give me regarding my visa inquiry.

I am a US citizen and I married a Thai national on June 21, 2019, in Thailand.

I opened up a bank account in Thailand on June 20, 2019, with sufficient funds greater than 400,000 Baht.

I want to apply for a non-immigrant “O” visa based on marriage so that I can live and teach in Thailand.

My questions are as follows:

Should I apply for the non-immigrant “O” in the US via the Thai Consulate in America or should I apply for a Tourist visa and then apply for the non-immigrant “O” visa in Thailand (if that is even possible)

Also, what date (length of stay) should I buy my return ticket? I would prefer multiple entry if possible.