Hombre! Bienvenido!
I'm spanish too
, from Murcia. I'm really happy of seeing other spanish people here!
If you want to focus on 2d games, and you already now a bit of C++ I recommend you to use my own library:
IndieLib. It is focused in rapid game development.
If you are planning of making Tetris, I made myself a tutorial some weeks ago:
http://gametuto.com/tetris-tutorial-in-c-render-independent/ It dosen't use IndieLib, because it is focused in game logic, so I only drawed rectangles using SDL that is really easy.
But if you visit the IndieLib link I provided you, you will be able to see the IndieLib tutorials.
Please, visit that link, you can ask me whatever you want through a private message, and... puedes escribir en español, faltaría más, jeje.