what can i do and don't in western culture?

You can't asking many questions. You have know about table manner

don't:
1. dont ask a women about her age or weight
2. References to someone's ethnic or racial identity are inappropriate unless the subject is broached generally.
3. don't ask a lot of question when you just meet somebody
4. Holding the middle finger up by itself is considered insulting and vulgar.

do:
1. Eye contact is important when shaking someone’s hand.
2. Stand while being introduced. Only the elderly, the ill and physically unable persons remain seated while greeting or being introduced.
3. leave a tip when you go to a restaurant 
4. One must address those significantly older than them as Mr., "Sir", Mrs., "Ma'am", "Madam", Ms. or Miss.