Be courteous. Discourtesy implies not wanting friendship. Formality in politics and diplomacy was not invented without reason.
Courtesy is required for smooth operation, without misunderstandings, in the society of strangers. This is particularly useful, if help or information is later required from those strangers.
Common courtesys: Hold heavy doors open for people who are just behind you. Follow the queue system. Shake hands. Stand when others are standing.
Say please. But, don’t overdo it.
Do not take anything for granted.
Include name with high frequency.