Good morning @ronbee,
Congrats on taking the first step towards wanting to improve your health and your heart. I have recently been working on weight loss and healthy eating also, as I also have heart disease and am overweight. I have gone to a nutritionist and she has given me the amount of carbs, proteins, and fats that I can consume daily. This has been helpful and there is an app if you have a smart phone that works well to keep track of this also. — FatSecret — is the app. Also, remember they even say walking 10 minutes three times a day can count as your cardiovascular exercise. The main thing here is to get your heart rate up. I wear a FitBit HR which helps me keep track of my heart rate In fact, by watching my diet and increasing my physical activity to five times a week, I have lowered my resting heart rate by over 15 points since January, which indicates I am improving my heart health. Also, I am going to copy/paste a website which is working on strength training using our own body weight. Remember begin slow and modify to your other physical limitations. https://www.nerdfitness.com/blog/2009/12/09/beginner-body-weight-workout-burn-fat-build-muscle/
Good luck. Sometimes it seems like we are not getting anywhere in our fitness, but small changes come and do not give up. We all struggle at some point in our life with something, but remember to push ahead and know you can do it.