Нужно ответить на 2 вопроса. do you think it is important for everyone to have good cooking skills? (как вы думаете это важно для каждого иметь хорошие кулинарные навыки? ) what would you recommend to a teenager to stay fit and healthy? (что вы порекомендуете тинейджеру, чтобы оставаться подтянутым и здоровым? )
But on other hand you can always learn cooking if you want. There are so many programs on TV and Internet besides books.If you have a wish you can always learn any thing you like. You are young and full of energy try yourself in cooking.
2. To stay fit and healthy you should eat healthy food and go in for sports. Of course you shouldn't smoke and drink energetic drinks and alcohol. It will be banal remark to say not to use drugs.