Your Walkera came with a gyro didn't it? That will complicate setting up the rudder (tail rotor pitch and tail servo) a little bit.
But you have to start somewhere like cyclic said.
Think of it like this: the heli is a fairly heavy thing, but in the air, it is sitting on a frictionless air bearing. It only takes a tiny push to get it to start sliding one way or the other, but the rotor head is capable of pushing it really hard in any direction. So the heli will drift and slide and bob around because of the push of the tail rotor, turbulence in the air, and slop in the linkages, and who knows what else. As you try to keep it in one place, your control inputs will inevitably be a little slow, so you will actually be pushing the helicopter the wrong way, or at the wrong time, so you will wind up correcting for your corrections.
Therefore, helicopters are impossible to fly. QED.
No, wait...