in my experience with weight loss, the first thing that everyone must fix is their nutrition. if you do not, then exercise may have zero effect on your weight problem.
that's not to say that applies equally to everyone in every situation. for some genetically inclined, a little bit of activity can shed the last bit of unwanted pounds. for others (most I would say), exercising won't make the slightest dent in your weight no matter what you do. Or, you'll find that you need to take exercise to the extreme in order to shed a few pounds which is most likely not suitable for most people (ie. ironman race training).
the biggest issue out there for modern society in terms of nutrition is processed sugars and carbs and the craving for it that is often present after years of consuming. you remove those and you will lose unwanted weight for sure. add in exercise and it will accelerate the process.