1. Running your 15 forms is a great warm up. You can start fairly light and by the end kick it up a notch to really stretch things out and get a full body warm up. This is my preferred method of warming up prior to class.
2. Here is a warm up I found on the net - its a good all over body warm up done in 30 second intervals at high intensity with 10 second rests in between exercises.
Squat and Hold
Plank on elbow
High Knees Running in Place
Pushup to Side Plank lift
I can't emphasize enough how important it is to stretch at least 3-5 times a week if not daily. Right now your bodies are building muscle and working hard. As you build muscle your body gets tighter and less elastic which can result in lower kicks as well as an increased risk of injury. Many of you are kids and your bones are literally growing faster than your muscles and tendons which naturally makes you even tighter so stretching is critical to being able to get through the Black Belt process.
You can find good guides to stretching on the internet - here are two I found - if you are under 18 years, please have your parents go out to these sites with you!