Getting on a treadmill for the first time can be intimidating, not unlike the first time on ice skates.
Here are a few suggestions to make that first treadmill experience a good one, quickly build confidence and develop good long term habits.
Start out walking when first getting on the treadmill. This is a good rule even when more experienced as a warm up.
Experiment with the treadmill controls while still walking, get used to the feel of the treadmill changing speeds and incline.
Look straight ahead, maintaining your normal running posture. The tendency for first timers is to hunch over and look down to stay centered on the treadmill.
If you need the hand rails to support you, slow the treadmill down until you are comfortable without holding on. Then start gradually increasing the speed again while maintaining proper form.
Once you become comfortable on the treadmill at a jog, adjust the incline. Since you are not experiencing resistance from headwinds, a 1pct incline to compensate and is similar to running on a level surface.