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.