Passport? Good.

Thailand

At restaurants

Ordering at street stalls, spice levels, and paying at the end.

A street food stall in Bangkok

Do you tip in Thailand?

Optional, and never expected at street level. Leaving the coins from your change is the usual gesture.

Ministry of Tourism and Sports (Thailand)
Diagram: a health ministry certification marks the kitchens that have been inspected

Is the street food safe, and is there any way to tell?

There is an actual certification to look for — Clean Food Good Taste, run by the Ministry of Public Health. It puts a checkable mark on what is otherwise a judgement call.

Royal Thai Government — Clean Food Good Taste certification
Diagram: the fork pushes food onto the spoon, and the spoon is the one that goes to your mouth

Do I eat Thai food with chopsticks?

No — spoon and fork, and the spoon is the one that goes in your mouth. Reaching for chopsticks is the most common visitor misfire in the region.

Royal Thai Government — Do's and Don'ts in Thailand

Sort the practical stuff before you fly.

eSIMs, rail passes, and airport transfers — the things worth booking before you land.