After the winter vacation of junior year, one year is enough for you to review for the postgraduate entrance examination.
I think you want to go to graduate school, so you must lay a good professional foundation. Learn more professional courses and learn more English in the summer vacation.
Take a professional basic course book for freshmen, read it from beginning to end, and work out all the related problems, which is very helpful for you to master professional knowledge. Then change one book at a time. These studies are not only conducive to your postgraduate entrance examination, but also conducive to your job search.
There are many preparation plans on the internet, all of which are the experience of predecessors.