I'll float a few answers for you.
1. Some say breathe through your nose, and out through your mouth. I say, just breathe. Don't worry about this. Your breathing efficiency will improve in time, becoming less labored.
2. Consider warming up BEFORE stretching. Stretching cold muscles can lead to injuries.
2A. Sore ankles can be a symptom of simply starting to run long distance. You take a lot of pounding. Try to stay off of concrete. It's the worst surface for impact. Asphalt is slightly better, but try for a smooth dirt trail, or grass -- something that gives a little. Shoes do matter, a lot. Spend the time to find a running store and have them fit you properly. If you pronate, supinate, or are a neutral striker, it makes all the difference in the type of shoe (stability control for example). All shoes are NOT alike.
If the ankle problem persists, see your doctor and or an orthopedic professional. Early treatment/prevention is the key.
3. Go to your local running store for programs. They will have local club information, local race information, and are a wealth of knowledge about cool places to run, etc.
You might also consider Team in Training, if you want to train and support blood cancer research. It's a great team concept with a worthy cause.