There are three components to a successful fat loss program:
1)
Strength Training - Focus on major muscle groups and compound exercises (bench press, leg press, military press, deadlift), don't worry too much about isolation exercises (bicep curls, calf raises, triceps, etc.). You can add those as you progress. Do 1 to 2 warmup sets at an easily manageable weight and 2-3 sets of 8-12 reps at a rate that brings you close to muscle failure. Concentrate on using good form even if it means using 5 lbs dumbells next to a guy who is using 100 lbs dumbells. It isn't a competition. To start with, your routine should take 30-60 minutes to complete.
2) Cardio Training - You should exercise at least 30 minutes per session with up to 6 times per week being desirable. Unless you are a strong swimmer, it will be hard to swim long enough to get a good cardio workout. Consider adding walking or time on an exercise bike. To truly maximize the value of your cardio workouts, you need to know your heart rate. A
heart rate monitor is the best way to keep track of this.
3) Diet - More fruits, vegetables, whole grains, and lean proteins; less processed foods and saturated fats.