Another beginners question

If you go to tools -> netlist veiwer -> RTL view that will give you a schematic view of the design at the RTL level. The post map viewer will give you a view of the design at the primitives level (luts and registers) - these are not the same as the schematic entry mode.

Quartus can convert schematics that you draw to VHDL - but I dont think you'll like reading the VHDL that is generates much. It is only really meant for simulation.

But as other have said, before you write any code, you need to draw your schematic on paper. When you get used to this, and you can think in schematics, then you can move more freely with the code. But with any design, the documentation should break the design down as much as possible before any code is written.