It seems daunting when you first arrive in country, but everything gets easier as you live here longer. Please feel free to reach out for any info or coffee. I am on a retirement visa, but may change to wealthy pensioner LTV next year. I actually need to see what Visa will allow me to tutor english, computers and guitar\bass lessons.
I have a phone with virtual esims, I have my US number and my True service Thai number. I am able to send and receive calls and text messages from anywhere without issue. When I am in Thailand, I use my Thai number as Primary and US number as secondary and all calls and text messages come through, When I am in the US, I simple reverse the roles. No issues. I went to a True store and they have many plans.