The DGIV's docking AP will only work if you are within 50k of the target, and have a low relative velocity. You need to align your planes and sync orbit's before you can use it.
While the DGIV's autopilots are handy, they won't fly the entire journey for you. Each does one task, and one task only. The ascent AP will get you from the surface to a stable parking orbit, and no more. The docking AP will dock your vessel - if your orbit very closely matches the target's, and you are close enough, but it won't align your planes and rendevous. The fully auto re-entry AP will get you through the higher atmosphere and reduce your velocity, but it won't de-orbit and it doesn't care where exactly you want to land.
Even with autopilots, a basic understanding of Orbital Mechanics and Operations is required to use them correctly and effectively. A good place to start is with the annotated recordings contained in the "Tutorials" folder in the scenario list. The above mentioned "Go Play in Space" is also excellent, and expands on the flight recordings. There are also dozens of other good tutorials - some written, some flight recordings, and some video, available.
I'm not trying to be rude or dismissive, but there are no magic shortcuts to Orbiter - it is real physics, and an understanding of those physics (as well as the methods used to apply those physics) is essential. It's quite likely that many of these tutorials won't make much sense at first, so read them, try it yourself, read them again, etc, until it becomes reasonably clear. That's what I did, and the same is true for almost everyone here. Expect dozens of failures before success is attained.