It is hard to compare the recovery of a C-Section to an Appendectomy. C-Sections are a must more invasive procedure than appendectomies, so the recovery time frame for a C-Section is going to be much longer.
I am assuming that your right side is tighter than your left after the appendectomy. The reason you feel tighter on one side rather than another is most likely due to the majority of the tissue damage that occurred during the appendectomy was inflicted to the right side of the abdomen to get to where the appendix is located. The tissue will scar and adhesions will develop between the muscle tissue and the skin tissue, causing restrictions in movement.
You can help this by either going to get treatment to try to break up some of the scar tissue or just doing some gentle friction massage over the area yourself. That plus working on the flexibility of the tissue will help decrease that tightness and improve the ROM.
In regards to returning to activity, follow your doctors orders on when it is safe to start activity again. You want to make sure that everything is healed properly and there are no chances of complications or damage to the sutured area after surgery. Once you are cleared for activity, just progress as tolerated. Start with light work and progress to more demanding activities as the area of surgery and your body as a whole adjusts.