Dont yell at him ,that would make him sensitive ,children dont like to be rushed around, allow more time, if it is in the morning to go to school ,get up earlier so no ne is running around getting het up.All children say 'dont knopw" thats pretty common we hear it every day.This isnt depression, dont feed into any negtives,i he is okay let him make his own frends and dont read into any situation that isnt there, focus on his positive side and praise him when he does something right.