Definitely talk to your doctor, I wasn't cleared for exercise for either of my c-sections for 8 weeks, and even then it was just cardio, she said probably 12 weeks before direct abdominal workouts.
Hi there...... you need to talk to your doctor about whether or not it's actually safe for you exercise yet.
I'd suggest that you look into some yoga videos or classes. Yoga is great for toning muscles, and also helps with weight loss. Walking is also excellent. Since it's summer time, put the baby in a stroller and hit the sidewalk; pushing the stroller will even help exercise your arms.
As for diet, a good healthy diet, with plenty of protein, lots of veggies, etc will be good. Figure out how many calories you need then drop a few, so you'll be in weight loss mode.
If you drink soda, eliminate that from your diet; switch to water. Switch to whole grain breads, pasta and brown rice, instead of white. Baking/grilling meat is best.
Fresh veggies are best, but if you can't do that, frozen is next best. Canned is least desirable, because of the salt content.