Riding a little bit farther than you've ever done before is always pretty darn satisfying. I think you're on top of things regarding food and water. Take a couple bottles with you and still plan on filling up at a park or whenever else you get the chance. For food I'd say plan to eat around 100 calories or so for every hour of riding. I'm sure some here will recommend more, some less. Everybody is different, so experiment and find what you feel works best for you. Properly fed and hydrated and you should find yourself feeling a bit stronger by the end of your ride.