Many great advice so far. Now you need a plan. Without a plan or without setting goals, nothing happens in the way you want.
Take actions now. Start with jogging/walking for 30 minutes each day. Jog 5 minutes. Walk 5 minutes. Repeat the jog and walk rotation 3 times. Do this for 5 days a week for 3 weeks. Then you can increase your jogging from 5 minutes to 7 minutes. Shorten your walk from 5 minutes to 3 minutes. Do this for the next 3 weeks. Then increase your jog from 7 minutes to 9 minutes. Shorten your walk from 3 minutes to 1 minute for another 3 weeks. You are building endurance. Then slowly you will be able to jog 30 minutes straight without walking in between.
You can jog in your neighborhood or in a park or in another neighborhood. It also helps if you are listening music from an iPod or an MP3 player while jogging to pass the time. Listening to music during exercise keeps me in the zone.
On the diet side, start drinking more water and cut out soda (advice from other posters). Here's what I have done before. I used to drink 2 cans of soda daily. I cut my bad habbit gradually. I allow myself to drink 3 cans of soda per week. My schedule was one can of soda per Monday, Wednesday & Friday. I did that for 3 weeks. Then I revised my schedule to only drink 2 cans of soda per week (one on Wednesday and one on Friday). did that for 3 weeks. See the pattern? I still love the taste of soda. But I don't crave for it anymore. I now have self control and only drink soda one can per weekend.
Keep tab of your weight once a week. Losing 1 to 2 pounds a week is normal.
So start making a plan and start acting on it next Monday. We are all here rooting for you. Tell us what your plans are for exercise and for dieting. Keep updating us on your progress.
You can do this! Don't think too much. Just do it! Start making changes on things you have control over your life.