我现在在国内上大一，大二申请了转学去美国读

既然是转学，如果是可以转学分的，就是说你在中国学校学的学分可以转成美国学校的学分。那就一定要好好学，如果挂科要在美国还要学的话就很不合适了。学一门课学费要两万人民币左右。
但是如果不转学分就无所谓了。

I had the similar experience. I transferred out of my Chinese college but had to start fresh from the US college.The main purpose to continue your second semester of your freshman at the Chinese college is to get credits which might be transferred to the US school. If you find it's very likely to get the credits transferred, go ahead. But most schools are not willing to allow you do it because they want to earn tuition from students. Therefore, try to ask your academic advisor with a list of the courses. If you do want to get the credits and save your tuition, convince the advisor that your courses meet their requirements. If necessary, show professor's recommendation to them.

准备你的语言吧，特别是写作，美国大学的很多assignment都是paper，这样对你将来适应那里的课程有帮助。

呵呵，人家不要你大一下学期成绩的原因是你没有。