Scenarios

your best friend blocks your number and cuts off all communication with you out of no where

Your best friend tells you that they do not want to be your friend anymore

You hear your friends talking about you behind your back to other kids in your class

People in your class tell you that they have heard gossip about you coming from your friend in class

You were supposed to meet your friend at the mall to hangout. They did not show up. You see them at school the next day.

Your friend has been ignoring you for a week. They walk into English class and start talking to you as if nothing happened.