What is the difference between "gens", "peuple", and "personnes"?
"Peuple" is a direct translation of people, but generally like what you see in government documents or general populations with a certain common aspect between them.
"The People of America" = "Le peuple des Etats-Unis"
"Gens" is used to describe the people in your area/around you. Oftentimes you can replace this with "ceux."
Les gens (ceux) qui vivent ici sont très sympathiques. = The people (those) that live here are very nice.
"Personnes" is used to describe a group of people that you see and want to describe (usually much more specific than when using "gens")
Ces personnes là ne sont pas mes amis. = Those people aren't my friends.