Most of the courses of freshmen in general colleges are basic, and the proportion of four-year credits is not high. At present, your grade of 3. 19 is not bad, and the two years with the most courses are sophomore and junior. The scores of these two years, especially the junior year, must be improved. You should have no problem reaching 3.6, and courses with more credits should be higher.
Junior and senior are related to the study of professional courses. If you can get beautiful grades in these two years, it will be of great help to your job search and study abroad. American graduate applications generally have requirements for GPA in the last two years, which shows that American universities have high requirements for professional courses.
If you are not nervous about a semester's courses, I suggest you choose more courses for teachers who are easy to get high marks, such as elective courses, which can also help you improve your overall grades to some extent. In addition, the results of the experimental class should also enter the total score. The results of the experimental class are very flexible. You should communicate with laboratory teachers more and get on well with them, and the experimental results are basically the main embodiment of your practical ability during your college years, which should not be underestimated.
I hope it helps. If you don't understand, you can keep asking me.