For the subdivision, a subdivision application is submitted by the surveying office, in which all essential building code-related points must be presented. Based on this, the building authority will either approve or reject it or formulate specific conditions for the subdivision. Usually, of course, this is discussed beforehand between the surveyor, architect, and building authority.
The building authority will provide little information mainly regarding costs. The building authority can only tell you, for example, what the registration of a building encumbrance or a building application costs. The building authority will also not be able to answer some other questions from your catalog without knowing the specific construction project. Since this planning does not yet exist, the discussion there will only be able to revolve around fundamental matters.
In other words: it certainly does no harm, but you will not really make progress there. At the latest after that, you will need an architect and a surveyor.
Best regards
Dirk Grafe