This site is being deprecated.
Please see the official X‑Plane Support page for help.
Which version of X-Plane 10 are you using? Mobile or desktop?
Mobile autopilot works by tapping the top of the device screen, then tapping the "hdg" "pch" or "alt" buttons. Tap a second time to turn it off.
On desktop, the switch to control the autopilot is found on the far right side, labeled "flight dir." (Autopilot controls are boxed in red in image below.) It must be set to "auto" for the plane to fly itself. The altitude button will remember the last setting and get you there if the AP is turned on, or you can set it to your current altitude.
answered Jan 20 by jroberts (3,855 points)
The autopilot in the default Cessna is pretty simple. It will only hold an altitude. So you'll need to get to the level you want then press the ALT button to have it maintain it.
Heading is controlled by the heading bug on the directional gyro. See the image below: the red box highlights the DG & the yellow box shows the knob to turn to move the heading bug.
Thanks jroberts, looks like I found the answer to my question.
This site is no longer being actively maintained.