Why i don't level up?

Free games ain't give CV... And cv is levels...

Because the game you gave away has been free at some point so no CV from it, indicated by ** after the name in the dropdown list.

You have to make a giveaway for a game that doesn't have 2 stars next to it. If it does, it gives no contribution value and therefore you do not level up.

Yup! What Ekaros said, you gave away a game that was free.
When you create a giveaway, check if the title of the game in the drop-down list has one or two stars (* and **)
In the case of one star, the game was bundled and you get only 15% of CV for up to five copies of the game.
In the case of two stars, the game was given away for free on some site.

Answer can be found in the FAQ under Contributor Value and Levels.