If you are only 14 you should be eating your parents out of house and home. Whole food should be your best friend. Pre-workout should always be carbs+pro+ healthy fat. The fat is there is slow digestion to keep the breakdown on a more consistant level through training. Post work is similar just cut out the fat and look to be in the range of 2:1-3:1, Carb to Protein ration(depending on activity level).