In a world every fill with individualism, we should strive to think of others. Sometimes it's difficult however there isn't a lot you have to do. Simply telling someone Assalamualaykum which means peace be upon you can be a means to change someone's day. Spreading Salam amongst people is the advice of the prophet Muhammad ﷺ (peace and blessings be upon him). Wether you know someone or not give salams. Below are the Arabic words of assalamualaykum taught by our beloved messenger ﷺ
السلام عليكم ورحمة الله وبركاته
Assalamualaykum
And to reply
وعليكم السلام ورحمة الله وبركاته
Walaykum Assalam