In everyday English, the plural form of person is people:
One person came to the English class.
Two people came to the English class.
The word peoples means two or more people groups:
There are various indigenous peoples living in the Amazon.
Many different languages are spoken among the peoples of Africa.
The word persons means "individuals" and it is really only used in very formal/official contracts or reports:
From a police report: Security camera footage shows that four persons were involved in the bank robbery.
Police also look for persons of interest (people who may be connected with a crime) and search for missing persons (individuals who are missing and nobody knows where they are).