@Maggie ********
If you are over 50 years old, you can get the 90-days single entry Non-imm-O retirement/over 50 visa by the e-visa online system in Australia.
You enter Thailand and receive a 90-days stay permit. You then need to open a Thai bank account and transfer a minimum of 800,000.- THB onto it.
Then after the deposit has seasoned for two months, and before the 90-days stay permit is expired, you can apply on Immigration for the 1-year Extension of the Stay Permit
There is no mandatory health insurance required for this visa.
Other options are the LTR wealthy pensioner’s visa, the ELITE Privilege visa and the Non-Imm-O/A Longstay visa