How can I live healthily on a budget?

This Saturday I'm going away to college. I'm going across the country to Los Angeles (My family's from upstate New York) and I want to try to be healthy. I haven't been the healthiest person living here, but I've decided that I would like to live a healthier life than I have in the past years. I'll be living in the Hollywood area, so any stores anybody knows of around there would help as well. But I'll probably end up at a normal supermarket. I'm not looking to start eating all organic food, as I won't be able to afford that ($900 a month for rent, $23,000 a year for tuition, and all the other expenses). But I would like to be healthy, and as cheaply as possible. I'm going to start running out there as well (If you know any SAFE places I can do that as well in the area, that would be appreciated). But overall, I'm mostly looking for things like cheaper food items that are healthy, and stores that tend to have lower prices for healthy options.