This app was mentioned in 2 comments, with an average of 1.50 upvotes
I can see you're having problems.
Please don't beat yourself up over simple mistakes.
Pizza one day won't harm you, or your weightloss.
Please look up:
https://www.choosemyplate.gov/teens
This website will give you good tips to stay on track and learn about food.
https://mnew.supertracker.usda.gov
This is a food tracking app made for a wide range of people, especially teenagers.
You can learn you proper calorie intake here and other useful information.
Here is some useful excercise links:
http://hasfit.com/teenage-weight-loss-for-teens/
http://hasfit.com/beginner-workout-program/ (recommended)
https://play.google.com/store/apps/details?id=com.zenlabs.challenge.squats
If you have a phone this is a nice app to do squat excercise.
Since you have a bike, you can ride it for 30 minutes a day.
Do the worry about intensity, you just want to bring you heart rate up.
For a watch around a $100 or so look up the fitbit charge 1
All for Android. I don't know what iOS equivalent there would be(but I bet the same app exists)
I never kept up myself once I reached the end, but it's a good way to build up to it over time.