Are there any differences between classes in college and the school? If so, how? Do the teachers expect your participation? How do you expect to be in the class? How to spend your time in the classroom?
Fortunately, ignorant and childish behaviours are within the university. Higher education students are assumed to be mature and serious adults.
There are some unwritten rules and expectations in the classroom. Always your advisers are busy with their research work but are still there to help you.