You just unboxed your Xterra XT900. The manual shows you how to fold it. It doesn’t show you how to not hate exercising on it.

If you use a chest strap (Polar compatible, not included), the XT900 can automatically adjust speed to keep you in your target zone.

Do not change values unless you are following a repair guide.

Familiarize yourself with the parts of your Xterra XT900 treadmill:

Here are the specifications for the Xterra XT900 treadmill: