Gels are a good energy boost but they don't last, the bars are better but anything with oats like flapjacks are good, malt loaf and bananas are great as well plus they take the feeling of hunger away. Make sure you are eating well before you go out on the bike, complex carbs(porridge, wholmeal bread, rice, pasta)
If training hard put a carb/electrolyte solution in your bottle also, and please take a day off the bike, even if you mix cycling with other training like light weight training, rowing, running or swimming, they will put other muscles into use which will make you a better cyclist.

As for always being hungry and no energy the best thing to do is work out how many calories you are using each day and make sure you are replacing them plus make sure you have plenty calcium and protein at your age!

Don't ever worry about questions being silly, this one is a very valid one and it's great to see younger folk interested in the sport. Keep going but take some rest, you will find the next day you will feel much stronger!