Are there any wrong grammar here?

on the third pharagraph, Grubbs mom went to his school and her face is white with rage and Grubbs know shes here to punish not to comfort. Grubbs groan and roll his eyes because he doesnt like his mom going to his school but his mom thinks its ok because its for Grubbs own good. His mom doesnt know like him smoking but Grubbs think its cool