I have shortness of breath, chest pressure, weakness, bloating. I am overweight. Best exercise?

CP. Before deciding on exercise we need to assess why you are having symptoms of chest pressure, weakness, and bloating. See your doctor to rule out cardiac problems. In general 30 min of walking every other day keeps you healthy.
Walking to your MD. Joking aside, the bloating and the shortness of breath could be explained by being overweight but you should not ignore the chest pressure. You should make sure it is safe for you to exercise before you decide to do so. You should see you doctor and at least start with an exam and ecg.