Im 15 help me reach my goals.I need to know all about weight loss and nutrition... PLEASE READ I NEED HELP?

Okay so i will start off by saying im 15 years old im 5'7 and i recently weighed in at 282 pounds. That was the worst feeling ive ever felt seeing this number. I am ready to change. I dont want to be "skinny" I want to be fit and healthy. I no have know idea where to start. In the past i would count calories and i ended up losing around 10 pounds, but i have problems staying motivated so i ended up gaining it back. I started homeschooling this year because of bullying as well as my insecurities. I also bought my own refrigerator because my family is unhealthy as well (all overweight/obese) I think that these two steps are the best start for me.I am a sophomore right now i would like to go back to school my senior year and make ever person that bullied me regret it.Now all i need is the motivation and knowledge. Again i want to be healthy please tell me everything i need to know. What would be a good weight for me? Is it better to count calories or carbs? Should i not be lifting weights until i lose the weight.