S. The best advice is to start slow and with something low impact that you can do anytime, anywhere. As suggested, walking is a great start.

Motivation will likely come as you progress. You'll walk further, faster and you'll see the results in how you feel and how you look. Adding in hills and / or stairs can further motivate you. I remember when I started 'jogging' (read walking and jogging for 30 seconds then walking again), just adding in extra blocks was extremely motivating.

As for the specific body areas - nothing will target one area in particular for fat loss. Fat is lost all over, and how you lose it is determined by how you gained it - it's in your genes. Doing a thousand crunches or leg presses won't force your body to eat that area's fat more than another area's fat. However, doing resistance work targeting those areas (and others) will ensure you have firm, tight muscles under the fat, so when you do lose it you'll look all that much better.

Cheers,
-N