After about 1 week and a half of RCing regulary throughout my days, I finally got lucid!
That was yesterday, I was in a dream where I had bought some stuff in a video store with my brother and cousin. The interesting part happens when we watch Shin Shan (in real life I found some Shin Shan comics) on TV :

There is some cartoon guy being pursued by a car, he lifts his arms and wants to fly but falls on the ground. That's when he says "if only it was a dream so I could fly"
I have the idea to RC so I pinch my nose and count my fingers without seeing them.
Just after that I heard a kind of military transmission and realized that made no sense and wanted to RC more seriously but I woke up immediately.

I'm happy I made it with a few reality checks a day
This morning I had the thought in a vivid dream "this is a dream so I'm not supposed to die" even tho I didn't go lucid, so I think I'm on the right way