Good for you! Exercise can offer a huge list of benefits to almost all of us, and can help us to enjoy life more fully. In addition to the fresh air, the movement and the potential to boost your mood can be positive events that improve not only the length of your life but the quality of it as well. With regards to your specific situation, it is important to speak with a doctor
before you begin any exercise program. This is because there are some questions that he or she may be able to ask that would help you to identify if you are at an elevated risk of having complications when you start into a more active lifestyle. Some of the common problems that can come (like you say, the can of worms), include heart problems that have been lurking beneath the surface. Not that the exercise would necessarily cause many of these, but it may expose them. This is best done in a safe and controlled fashion, which is why speaking with your doctor before hand is vital. Please speak with your doctor about your desires, and best of luck in this!