You can try to do calisthenics: Push-ups, pull-ups, bodyweight squats, and dips are great exercises. Now if you are very overweight and can't do these exercises regularly don't worry you can modify them so you are able to do them.
For pull-ups using bands(the larger the easier) for doing push-ups you can put yourself on an incline by putting your hands on a bench or chair with your feet on the ground.
If you need to lose a very large amount of fat though I would fast. Fasting is simply the fastest and most effective way to lose fat there's already a thread here though so look there if you want to learn more about it. Basically just don't eat and drink at least 2L of water a day is what you want to do though.