It might be a simple misunderstanding on my side of course but I just don’t get what you mean when you use the wrong terms. That’s why I recommend to watch tutorials at youtube since they SHOW what they do while they talk.
Example: A “course” is a direction towards a radio station or a waypoint in aviation and you don’t set it anywhere manually during a typical flight on an Airbus. What you dial in are headings or tracks.
Flying an Airbus correctly is certainly not simple, when I said “too much to simply write down in a forum post” it meant that it’s too much and too complicated to write it down within a forum post. It’s much more helpful for you to google for the actual FCOM (flight crew operations manual) and work yourself through the related parts.
What I explained above is the very very very basic understanding of the FCU (autopilot panel) and there is a lot going on behind the scenes depending on whether you push or pull a knob. The boxes above the turn knobs and the FMA in the PFD give you information about what modes you are in as mentioned above. An Airbus, not even the totally default one, is not a jump-in-and-succeed aircraft, it requires a bit of research and reading. The trainings that come with the sim are, excuse me, garbage. As unfortunate as it is.
The basics: if you want to make the aircraft fly into the direction you want it you need to dial the heading into the box and then pull the knob out. There should appear an arrow down whn you search the clickspot in “legacy” mouse settings. Same for the speed. to change altitude manually dial the new target altitude in and then right next to it select the climb or descend rate and pull the VS knob out as well.
If you pull a knob out you want to take the control to you, if you push it in you give it to the airplane.