Eating sensibly isn't brain surgery. Just don't eat fried foods or too many simple carbohydrates (like white bread and rice, sugars) and you'll be fine. Start drinking skim milk and after a while you won't even want the taste of whole milk. If you drink sugary drinks like soda or juice, just start drinking diet sodas or water or even gatorade.
Unlike the others, I'm gunna say if I was you I wouldn't even bother doing any cardio for a month or so. Just hit the weights for a month and then start doing some moderate cardio on your off days. Theres nothing more boring than going to the gym and running on a treadmill for an hour if you've never done it before.