Workout at the gym after break?

I started back at the gym after a 2 mth break and have been going for 2 days, I am fairly fit and manage to do around 8km on the treadmill, 10 min rowing machine, weights and ab exercises. Today I feel sore and legs heavy, should I go today and what could I do at the gym, I want to go but my legs are heavy, targeted areas is stomach.