Warm-up: Light stretching. Here is a new 8 minute stretching video. This one has some yoga elements in it, but very easy. I want to keep changing these every week so you don't get too bored. If there is a previous warm-up video you like better, by all means, go back to that and do it. Only do what you are comfortable with.
*30 minute cardio. Walk outside or on treadmill, elliptical or bike (recumbent, upright or AirDyne). Moderate pace. Commit to doing this workout 4 to 5 times a week.
*2rds, 20-air squats, 10-push-ups, 20-sit-ups. Modify as needed.
Air squats-find something to put under you bottom as a guide for how far to go down to. Make sure it is a comfortable depth, not too far down. https://www.youtube.com/
Push-ups-you can do them from your knees or even standing
against a wall. https://www.youtube.com/
Sit-ups- Feel free to do crunches. DO NOT place hands behind your head. That only puts undue pressure on your neck.