If you are healthy and just overweight, start with your diet. You need to eat clean and
in smaller portions but leave enough room for splurging a small bit everyday and then a big/better treat once a week so you don't feel deprived. The key is a calorie deficit. For exercises, I recommend Zumba or kickboxing, personally, because it makes you feel like you are doing something to workout and learn something for day to day life (Zumba, dancing; Kickboxing, self defense).