Dana,

The best thing you can do is ease into cardio. Honestly. If you are not use to working out, then keep the heart rate between 55 and 65 percent of your maximum heart rate for the next three to four weeks. This is not an opinion but actually a guideline that the ACSM has put out for Personal Trainers to follow in conditioning clients. There isn't really anything you can do to feel better after the fact, other than taking it easy during. Don't worry so much about what others may or may not think, it's your health and you are taking the steps to get in shape.

I personally do not eat right before a workout. If you do chose to eat something, go for a light snack and wait 45 minutes. If you eat a heavy meal wait a couple of hours.