Well at 10 I wouldn't suggest working out with weights, you're too young to start that IMO. But running/playing sports is a great way to lose some weight. But if you're eating snacks throughout the day or are eating unhealthy foods like fast food, bacon, mayo, etc. than it doesn't matter how much you run because you won't lose the weight. Eat healthy, go running. 30 minutes of cardio a day or more.
And as for having heavy parents, that doesn't mean you're automatically going to be over weight. If its genetic that basically means it will just be easier for you to gain weight than others. It means that you have to be extra careful about what you eat. Eat smaller portions and ask you're parents to cook you healthy foods. If you're eating snack foods and find it difficult to stop, tell you're parents to stop buying them. If they're not in the house, you can't be tempted.