Good Workout Help Please?

I'm 17, I'm 5'1, and I weigh about 130 pounds. I'm going into my senior year and I just really want to lose some weight over the summer, just like 10 - 15 pounds. I plan to do like wii sports, wii fit, or DDR for 20 mins. And like crunches, pushups, weights, for 15 mins on top of that. Both 6 days a week. And I plan to walk or ride my bike for like 30 mins at least 2 days a week. I'm also going to cut back on junk food and try to watch what I eat. Does this sound like a good plan? How long do you think it would take to reach my goal?