Do you go to Boston University by any chance? If so, it is famous for grade deflation (or the absence of grade inflation). In any case, not doing as well as you expected is absolutely normal, especially in freshman year.
Several posters above suggested going to office hours; in addition to understanding the material better, you’ll also show to your professors that you care about their class and put that extra effort into learning this stuff. This may well add some extra points for participation to your final grade.