To be honest if you are a beginner and you want to create a game without using a third party engine then the steps to writing your engine is this.
- Dont't write an engine. Just start writing your game and finish it.
- Now you want to write another game.
- Hmm I can reuse bits of my previous game to write my new game
- GOTO 1.
Follow these steps a few times and you will soon discover that you have a library of code that you know perfectly and can adapt to suit your needs and your coding style. This is your engine.
There is the alternative way which is to try writing perfect systems upfront but you will never finish because you will read an article that differs with the way your engine works and then keep restarting and could spend the next 20 years trying to write the perfect engine. Don't forget ALL successful games engines from simple ones like cocs2d to Crytek are permenantly under development.
Hmm I see what you're trying to say. Thanks!