Can i lose weight by eatting cereal and cardio?

Iam 5'5 or 5'4 17yrs old and weight 141-142 pd's....i have a some chest fat and some belly fat aswell and would LOVE to get rid of it....ive been eatting only Fruity Pebble's for breakfast and dinner and have drank alot alot of water for the last 2-3 days(since around July 3/4). I also been playing soccer throughout the day and been doing 10mins on my staionary bike...30 crunches and 30 sit-ups everynight....but i also dont want to do too much running cuz i have tendinitis on my right knee. If i go the way iam going will i be able to lose that weight? and what are some good cardio i can do that doesnt involve running but intense at the same time