Underlying what jbadams wrote, find existing libraries. Understand that making games in 3D for beginner developers (and intermediate in many cases) should only involve high level coding languages. Do not try to reinvent the wheel, but take a development framework, such as already suggested several times by people here, and learn how to code in that framework.
Especially for 3D games, maybe more than all others, workflow pipeline must be in your mind. We are talking about your assembling a complete workflow pipeline of applications and software for creating the coding and the art content, then using the tools which already come with the development framework (such as a game engine, for example) to implement coding and import art content.
Part of your problem is that you have not focused long and hard enough on one framework to ignite real application and game software development. This takes TIME!
You also need to work harder with already existing learning resources that were created for a specific development framework. Find tutorials, framework documentation, and other resources to begin to understand the workflow pipeline and the order that things are created within that framework towards completing a game.
It is a step by step process of moving forward and revisiting many issues in iterations. I hate to burst anyone's bubble, but long term will not allow easy methods if you care about substantial progress. Game development is a tough occupation for everybody who does it, so you just need to get used to tough mental focus, hard work, and discovering the logical step by step path to climb that mountain.
If this is a hobby, then have fun, but you still need to work harder and focus more on a prescribed path for game development.