Right Leg Cramp

First clarify: "Right leg cramps" vs "right calf sore"
Muscle soreness can be due to your muscles being "out of shape" and not used to the new activity (how often do you ride? what distances?). You may be "pulling" or "pushing" more with your right leg. Most people will "favor" one side or the other, so work on your pedaling technique; try pedaling with one foot unclipped and then switch to the other foot. If the soreness persists, it could be due to a fitting issue... maybe your right leg is shorter/longer than your left OR your saddle is not at the correct height... when you added pedal clips, it actually changes the saddle to pedal distance depending on your shoe sole and clip/pedal "stack height" OR the shoe clip is not at the correct angle. Give it a few more days and see if it goes away. If not; try the fitting fix (go to your LBS)
Cramping is a different issue, it can be due to muscle fatigue, dehydration and who knows what. There are several threads on "cramping" and what works (for some people) to eliminate them. On the last century I did, my left leg was cramping so bad that I had to do the last 8-10 miles standing up...