That's an ok plan. Let's talk about reality. First, you need to study some books about nutrition so you know how to eat right. Example: Figure out how much fat you want per day and get it all for the first meal. Fat slows digestion so you have a steady supply of energy all day and you don't get hungry between meals.
Second, the hardest part of any exercise routine is boredom, and especially if you don't get some results immediately. Fat is made of carbon and hydrogen. The only way it comes out of the body is if it is turned into carbon dioxide and water and then it comes out through the lungs. So that involves a lot of heavy breathing, and that means jogging or aerobic dancing. Figure on losing one pound per week when you are doing things right. That is your goal: one pound per week.
Situps are nice because you can do them so well and you look really neat doing them. But they don't really have much benefit. A situp is not a belly reducer, it is a hip flexor exercise. Your hip flexors are probably ok just because you walk around.
For stretches, sit on the floor with the soles of your feet together. Take your toes with both hands and lean forward as if to pull your forehead to your toes. Go as far as you can, hold a few seconds, then relax for half a minute or so. Do it again, but this time lean forward one inch farther. Hold, then relax. Do it a third time and go 1/2 inch farther. Do it a fourth time and go 1/4 inch farther. That's all for now. You may do this any time you like, but DON'T TRY TO HURRY IT! It takes three weeks to get loose. If you try to hurry you will hurt yourself and you will have to wait for it to heal, and then it will still take three weeks to get your forehead to your toes.
Squats -- this is such a goofy exercise you won't believe it, but it is very beneficial. Find a tile floor so you can keep your feet at right angles. Slide one foot backwards, more than half your weight on that foot, and keep it on the lines. Look ahead of you and find something vertical, such as the corner of the room. Align your body to the vertical. Look to the side, over the other foot, and find something vertical. Pull your hips in and align your body to the vertical. This is what you did those stretches for, so if you haven't put in at least three weeks on them, you probably won't be able to do this well. The first time you try this, your leg will be ready to give out at this point, so immediately slide your front foot to the back, be sure the feet are still at right angles, and shift your weight to that foot. Align your body again. Do this exercise all the time until you can do your homework standing in this position.
Legs -- Lie on your back, legs under a table. Put one foot (not the whole leg) on top of the table and lift your weight. Do it again with the other leg.
Arms -- Get a stick about two feet long and hold it in one hand with your arm straight. Wave the tip in a very small circle. Smaller. Smaller than that. Do both hands for equal times. This is an exercise for swordsmen. This will grow your arms like FOUR INCHES BIGGER!
