I am trying to avoid gastric bypass and started working out. but my body is so sore, mainly my legs and back. what should i do or take?

Start Low / Go Slow: Take Ibuprofen or Naproxen with cool compresses. Hire a trainer if possible to help guide you to exercising properly so you don't overdo it and injure yourself; then you can increase your intensity as tolerated. Swim or do water aerobics in between for less intense exercise. Remember to include a healthy diet with meal planning and portion control (try food diary app), and get adequate sleep.