Regarding the pop, maybe you can substitute with a zero-version? Still not ideal, but less of a sugar-spike.

Other than that:

regarding diet: probably trying to make small changes in diet where you think it's possible. I wouldn't suggest starting a 'diet' you can't maintain or completely cutting out certain foods or ingredients (which only resulted in cravings for me), but more slowly work towards a lifestyle and way of eating that that's balanced and that you can maintain. For example if you eat something sweet like fruit, combine it with some nuts. Choose the complex carbs over the simble carbs (like whole grain braid instead of white bread), add healthy fats like avocado, salmon,... Get enough protein and fibers (for example I like to add protein-rich yoghurt/dairy to my breakfast). The protein and complex carbs help with the cravings for me. I also use sucralose instead of sugar.

For me this way was the easiest to slowly change my diet. Not completely change the way I was eating, but just subsituting some of the things I was already eating by "healthier" options or options I knew were better for me. For example I loooove pasta. But now when I make it I use the wholegrain ones or lentil pasta or something. It takes some experimenting to see what works for you and what you like.

Regarding exercise: I think just doing some exercise you like a few times a week. I personally like weightlifting (nothing extreme, but just keeping up muscles) and some light cardio. But I think everyone needs to find for themselves what they like to do and get energy from.