Then you'll need a whole lot more documentation than I can easily provide.
But probably the best way to proceed is to think about what you need right now, your primary goal: whether it's lateral construction limits, ditch elevations, or whatever.
Then figure out what all you need in order to get it. Consider the level of precision you need at the moment, as that will tell you whether you need to worry about superelevation. (Superelevation is simple and quick once you know how to do it, but it's another step that you don't already know--assumably--how to do, and if you don't need anything super precise, it might be fine to leave it off.)
You'll almost invariably need an alignment and profile. That's pretty obvious. Unless all you're looking for is the surface of a paved road in space, you'll also need an existing surface (or any other surface to which your cross section will be tying). (That existing surface will need to be set as active in the file where you're creating the corridor.) You'll need to tell Geopak *what* to construct, whether it's a 2-lane road or whatever. (In OpenRoads, the typical section is called a template; the template drop is the application of this template over a range on your corridor. The corridor is a set of one or more template drops.)
You'll need to tell Geopak any special features for deviations from that typical section, like side slopes, clear zone width, pavement width, etc., using one of a fairly decent array of tools at your disposal: for pavement width, either attach graphical elements or assign parametric constraints to establish lateral offset. That sort of thing.
From here, it gets a whole lot more complicated, especially when dealing with local roads and merge and diverge gore areas, etc. I won't even bother.
But I guess I just covered design, and that's not what you were asking about. lol. And now I give up because, as I said at the top, I don't even know where to start, for plans production.