Moving to CM this fall. (Chiang Mai)

After many decades of living as a traveler around the world, spending "long Times" in Thailand and keeping a home in America, I am DONE ! The costs, TAXES etc.... To much ! It is now MY time to retire in CM. Haveing sold most all my "stuff" I'm on my way! i will be arriving in CM early this fall. All requirements for retirement visa in place. Looked at most all new \ relevant info online. I have done my homework. Now I request some info from you that have made the jump to CM.
On arrival in CM, can you recommend a quite guesthouse or a place to live for a month ,while I look for my 12 month lease. Is it best to contract health insurance befor or after arrival? For visa, 800,000bt in bank or monthly income (social security) or both? Any ideas /info welcome. Looking forward to hearing from and seeing you soon !