If the air conditioners are working properly that about 1500 to 2,000 per month for both water and electricity and I keep both by air conditioners running all the time
You can get a SIM card and a 60-day plan at either the airport or at 7-Eleven once you get to your hotel. The advantage of getting it at the airport is they will either set you up with an esim or put in a new SIM card for you.
I maintain a box at a UPS Store and that's where all my banking, social security information is sent to. Next year I will change that to a virtual office that will scan all of my mail and then I can decide which ones I want to have sent to me here in Thailand