Your question is analogous to saying: I have all this lego, what do I need to do in order to build a "thing"?
It's unanswerable abstractly.
When starting to a build game, you can't do anything before you decide on some starting points:
- what's the experience of the game?
- how is the world viewed?
- does it have a character, and if so how would that character be controlled?
All of those things would drastically change your fundamental building blocks, and only then would you go about thinking about the architecture of your game code (if you were so inclined). Personally, I think it's more productive while prototyping a game idea to just throw functionally down in any crude way to see if it's actually fun. Often it isn't.
Once you're onto something, good code architecture is important for maintainability and extendability depending on the scope and purpose of the project. For example I try to maintain very good structure for any large project (longer than say - one month of dev), but I generally don't bother at all on a Global Game Jam entry.
If on the other hand (interpreting your first post slightly differently), you're just talking about the best way to have an update loop, global engine constants, etc.. Then I guess it is just a matter of reading a few good articles.
