Mission - Build a dock - Q. how?

[dark helix]

I am on the mission 'build a dock'.
Unless I missed something, there are no instructions on how to build a dock during this mission.
So I went into the map, right clicked on the location, chose plan build (or similar) and added a dock, then nothing happened.
I guessed that I should add some money to build the dock and raise the budget for the project and then other ships (traders?) slowly start arriving but nothing is happening, no building and the required resources are not filling up.
I also need to find a builder but my co-pilot won't let me reassign her.
I am really struggling with zero guidance.
I want to love X4 but it keeps laughing at me and that is slowly starting to wear on my patience.
I have been playing EVE for a decade, so I am used to steep learning curves but this is just guesswork.