Question

1. My school friends are funny.
2. My classmates are funny.
[Do you use #1 frequently?]

Answer 1

Both might be said. "School friends" would apply to the other students one considers his or her friends at school, even if they are not in the same class. "Classmates" means all the students in your age level in the same grade (Class of 2017), or those in the same math or history class, etc.

Answer 2

UWU