If you carry it with you will remember to drink throughout the day. You will be impressed with the improvements in how you feel from drinking more water. If you don't like the taste of your water or have trouble drinking it, try adding a squeeze or two of fresh lime, lemon, or orange juice. You can't afford not to exercise. A sedentary life style will catch up with you and you will soon have to spend loads of time dealing with the consequences.
Exercise is fun.
Find ways to do some exercise or sport at least 4 times a week. Start off gradually about 20 minutes and work your way up to a longer session. Make a pack with a friend or neighbor and go to class, ride a bike or walk together 4 times a week. Take time for yourself - Take yourself out on a date once a week. Go to the movies, have a sandwich in the park, browse in a bookstore or go to a museum.