"Game Engine" is a generic term and topic. There's no specific way to make an "game engine". Besides that you show make games not engines. Engines are what you can extract afterwards.
The SFML Game Development books shows from start how to create a game with SFML 2.x.
There are hundred of tutorials on game development on the internet. If you know how to program and can make use of the official documentation and tutorials, you should have no problem adapting those tutorials for SFML.