I bought a guitar, now i have to start to learn it...

There are million sites online for learning the guitar. But you're looking for a systematic way that would be the most effective for you. The only way to this is with a private teacher. He's the only person who will be able to take your goals and transfer them into a lesson plan step by step. There are many free videos on YouTube for learning the guitar as well. But I would be careful with them.

When I bought my guitar, I found that the best thing that you could be able to do would be to look or chord patterns on the internet, and learn them one by one. Soon, you would find that you were able to play enough chords to be able to get a whole song together, and playing your first song will be something that is very rewarding for you. One of the things that I used to do would be to look on the internet and see if there were any songs that I liked that had simple chord patterns, and if there were, I would use these to learn the songs with and I found that it was much easier to be able to learn this way than it would be to learn the chords without actually having a song to be able to play them along to.

there are plenty guitar lessons that are in the internet. but you know you kinda learn the basic lessons just by picking a simple song and getting a guitar chart. once you can hear the tune of that simple song you begin to learn how to play the chords then you build your way up. Also you could go to YouTube there are people who post good guitar lessons.