It's recommended to do about 150 minutes or 2 1/2 hours of moderate-intensity physical activity each week. Studies have shown that regular physical activity can help support weight loss and long-term weight maintenance.  Aerobic activities can include exercises like: walking, jogging, swimming, biking or hiking. Exercise is a great support to weight loss, but it is only part of the weight loss picture.  Exercise alone will not always cause weight loss. The best combination is to do aerobic exercise along with a calorie-controlled diet for the best results. Weight lifting or resistance training is another important part of your exercise routine. Try to include about 1-2 days of strength training each week for the best weight loss benefit.  Strength training includes activities like: weight lifting, Pilates or isometric exercises like push-ups or crunches. Avoid doing strength training every day. It's important to allow your muscles to rest and recover after each strength training session. Making a consult with a personal trainer is a great idea to help you get started with an exercise routine. These fitness professionals will be able to show you how to use a variety of gym equipment, design a workout plan for you and may help you stay motivated.  Check with some local gyms to see if they are offering any discounts or specials on personal training sessions. Many times they'll offer a free session if you sign up for the gym membership. Although multiple personal training sessions can be expensive, you may only need a few so you can learn the ropes of the gym and an appropriate workout for you.

Summary:
Do cardiovascular exercises weekly. Perform strength training weekly. Meet with a personal trainer.