You should also use fresh paper. Kodak RC paper will be several years old and may not be in good condition anymore.
But as others have pointed out, your negatives need attention first. Before you shoot any more important shots, do a film speed and development test.
Bracket a whole roll of film, maybe 3-4 shots exposed at a range of EIs. If you shoot 100 speed film, try at EI 25, EI 50, and EI 100. Develop normally. Then print the negatives with normal filtration (Grade 2) and focus on the ones where you get good shadow detail without trying too hard.
Then shoot a whole roll at the speed at which shadow detail was best, and cut the roll in thirds. Develop one of the thirds, print those negs, again at normal filtration, and focus on the full tonal range of the print. If your highlights are weak and dark you need to develop longer, and if they are very bright and blocked up you need to develop less time. Adjust and develop a second third of your film, and print the negs again.
Once you have established a good compromise between shadow detail and highlight detail - or overall negative contrast, you are in a good position to start using alternative filters and make adjustments, but it's always always better to get your negatives somewhat tuned into what your paper of choice is capable of first. It makes for much easier printing, with a lot less waste (so it becomes more economical and less frustrating = win-win situation).