如果你不想去上课，以下是一些表达方式，你可以根据自己的情况选择合适的理由：
直接表达
"I don't want to go to school because I have something important to handle at home."
健康原因
"I can't go to school because I have a bad cold/fever/stomachache."
家庭原因
"I need to go back home because there's an emergency in my family."
旅游或外出
"I have planned a trip and won't be able to attend classes for a while."
交通问题
"The transportation to school is not convenient right now, so I won't be able to go."
记得在请假时，向老师或学校提供充分的理由，并表达出你希望之后能够补上课程或跟上进度的意愿。同时，考虑到父母的意见和感受，提前与他们沟通你的计划，并尽量说服他们理解你的立场。