If it is because you need your Thai bank to send you a code by SMS to the US : 1. Buy a Thai SIM card while still in Thailand 2. Register the phone number at your bank (must do it personally) 3. Go to the SIM provider office (ex : True Move...) and ask them to activate international roaming (must do it personally) 5. Make sure you have enough credit on the Tel. App before going to the US (you can always recharge it from abroad). 6. When in the US : swith on the Thai SIM for messages. 7. Your bank send you the SMS for free. 8. Once finished, swith off the Thai SIM. Good luck...
No. Either you get a Tourist visa in a Thai embassy or consulate in India, or you just show up in Thailand and you get a free 30 day exempt stamp, which you can extend once for 30 more days for 1'900 BATHS.
Book a guesthouse for the first 2-3 nights, get there, chose the surroundings where you would like to live, check real estate agents around. The safest, the easiest.
If you are travelling on a valid US passeport, you don't need a visa. When you arrive at the airport and pass immigration, you will receive a free stamp that will allow you to stay in Thailand for 30 days (make sure you have 1. at least 600 USD in cash 2. A accomodation booking for the first days 3. An exit air-ticket for date shorter than 30 days. If you want to stay more than 30 days, you go to immigration office in Thailand and buy an extension of stay of 30 more days, for 1'900 Baths (at 60 USD). The details are on Google...