Typically with people i encounter at bf above 20% their main probelm is a lack of quality nutrition. Most of their meals involve eating out and sporadic eating patterns.
My advice without knowing a lot about you:
Start out doing your cardio (20 min - 4x / week), Start increasing 5 min / session every week. At your age i would stick with using a non jarring cardio machine (elipitical would be excellent). Max out around 60 min. Starting low and working high will ensure you don't hit a plataue. You can always add a fatburner down the road.
As far as workouts go - Use a 2 on / 1 off - 2 on / 2 off system
Ex:
Chest/Biceps
Quads/Hams
OFF
Delts/Tri/Calves
Back/Traps
OFF
OFF
I don't know your recovery ability so you'll need to determine sets. I would try and stick with reps of 12 - 15. At low maybe 10 on some compound movements.
As far as your dieting eliminate foods that are processed. I wouldn't be hell bent on trying to change your whole life right away. However once you start to get used to typical healthy foods, start eating about 1.5g protein / lb Bodyweight and 1 - 2g carbs / lb bodyweight (varying in between ED). Keep fats low.
Hope that helps its pretty general, but thats about all we had to go with.