If you've never exercised it can seem overwhelming.
Start with SMALL goals - say a 10 minute goal to exercise. It's called a STREAK and do it EVERY DAY!
Record your activity on SparkPeople - it can be anything. My favorite is the Gazelle, because I have double knee replacements and it doesn't hurt - but it can be simply walking. THE REAL POINT IS NOT TO MISS A SINGLE DAY OF THAT 10 MINUTE ACTIVITY! This WILL soon grow to more and more exercise.