Is it normal to feel sore after your first judo class?

Absolutely normal to be sore after your first judo class. You're using muscles in ways they're not used to, plus the impacts and controlled falls put stress on your body that most people don't experience day to day. Most folks feel it pretty bad in their shoulders, hips, and legs for a few days after. The soreness usually subsides once your body adapts, so don't let it discourage you from going back.