First I suggest start reading some tutorials rather than jumping right in. My first project was doing the ghost shooter basic tutorial. That helped me understand how to put together C2 games. I then read the manual on the components.
However to answer your question.
* Assign your sprite the "Custom Movement" behaviour
* Add the Keyboard plugin(or mouse if you want to use that)
* Create an Event to watch for the spacebar
-> Keyboard Space is down(action : sprite accelrate at angle(20 force, -90 angle)
* create and ELSE event to the spacebar
-> ELSE( action: sprite accelerate at angle 30 force, 90
fine tune the up and down controls.
and now your done.
I strongly suggest learning by following the instruction of a few tutorials. the bird flight controls are super simple using C2.