I think the key here is get yourself on the course of healthy first with a couple of little things, and let the domino effect take over. It sounds overly simplified but healthy really leads to more healthy and bad habits lead to more bad habits.

Exercising is definitley the first step, even something small. that will make you more proactive in trying to eat healthier.

As far as smoking, I know several people who have quit using smoke aids like the patch. The only way you can truly quit though is to find some leverage, some reason you absolutely have to stop.