it's less about what foods to eat and more about eating much less: one modest-sized meal a day. that's all we "need". we eat too much of everything and our bodies are not evolved for such excess. this is literally the biggest bang for buck for chronic diseases like this, but also the hardest thing to do because of socio-cultural considerations. it also takes some time to train your digestive system down to that level.

once you have amounts under control, then you can taper off the processed foods, especially sugary things like soda/juice (fruit is ok because it comes with fiber), salty things like chips/frozen dinners, and bread/rice products (a little whole grain here and there is ok). minimize processed foods but don't worry too much about the mix of foods otherwise (protein/fat is fine, just don't overeat).

then taper up anaerobic exercise to 2-3 times a week. find a sport or activity you like (e.g., tennis) and pay for an organized league/class so that you stay committed. (aerobic) walking, for instance, is not typically strenuous enough for your body to process the excess nutrients and improve cardiovascular fitness, which is what's needed to help keep heart disease under control. you can start with walking if you're in bad shape, but you'll want to graduate to anaerobic exercise as soon as you can.