To ease any soreness you may have, I recommend foam rolling or taking an epsom salt bath — just keep moving!
Today's workout is going to be pretty light. If you're a beginner, I recommend doing a light form of cardio like a 15- to 20-minute jog, cycling, or swimming. If you're more advanced, aim for 30 minutes of cardio. Whatever you choose to do, know that it doesn't have to be extremely intense; today should be treated as an active recovery day which means you're allowing your body to recovery but still moving around.
If you're feeling really sore, I recommend following a yoga flow or going on a long walk. Don't forget to get some rest tonight, because tomorrow, we're strength training.