Set-up google voice number. Can be used to make calls to/from USA like normal.
Probably your N. American phone wont work here (Wifi will) you will probably need to get a new phone when you arrive. Work it out friend/family to use their phone number for your Google Voice number.
I recommend packing light. You wont need a big wardrobe and clothes can bought cheap here. You will be most comfortable/lite clothing, t-shirt, shorts, flip-flops. I brought two duffel bags of clothes, haven't open since I arrived.
Extra passport photos come in handy. You may not need them but you will use them if/when you get extensions new visas etc.
If you plan to go to another country after Thailand - you may want to get an international drivers permit (sometimes mistaken call license). I don't recommend driving a car while you are here and a license isn't necessary for a motorcycle (scooter).
If you plan to work while you are here, stop by local courthouse and get a transcript that says you have no open cases (no cases is best). If you are unable to do that at a local courthouse, go to a courthouse where you can (next city or next state).
If you plan to earn a income from the USA and import the money here, transferwise is your friend. Requires a local bank account, you can worry about that when you are here.
If you plan to be out of the USA for more than a year and do not own property. Check with whatever state you paid state tax, to see requirements for being a non-resident. Tax burden's a bitch.
Bring Twizzlers. When you arrive PM me.. I will send you my mailing address. ( I tease).
I have a Volunteer Visa. I am in Pattaya - PM if you want a Pattaya Recommendation.
I do not advise the ED visa. A Immigration Officer at the Airport told me its not a good option for my age group (at the time I was 40). (stands for Education NOT Erectile Dysfunction)
Do you mean a car? My recommendation is get a taxi. No kidding. The people here would love the work. It cost me the same to rent a car as it does rent a car with a driver. Driver knows the law, knows the language, knows how to get of tickets.
Of course, if you're only tooling around town a motorcycle does me quite well, no license required.
I got my police clearance report from the local court house. It said I had no open cases. Nothing more. That was satisfactory for Ministry of Labor (or whoever asked for it. I dont exactly recall).
Additionally a buddy of mine got theirs from a local municipality. His parents had to get for him and send via post.
Both instances was about 5 years ago. Things may have changed but I kinda doubt it. There certainly a lot of confusion on the matter.
The question I would ask, if I were you,
"Has anybody in the US recently obtain their criminal record/report, what did you use? where did you get it"
If you ask that way, you likely get answers from people who have experience instead of people who believe they are good guessers.