You are not hindered to say or publish what you believe in. You are not hindered to associate with like-minded to support whatever cause. Thus it is clear that libertarians are mainly concerned about negative freedom. Libertarians want to defend negative freedoms which exist and to extend the areas of negative freedoms. Example giving, libertarians want to remove the hinderences to decide on your and your children's education.
Libertarians tend to distrust the conception of positive freedom.
They fear that their pure theory of liberty is watered down by introducing the idea of positive freedom. They think, coercive measurements are necessary to enable people to use their freedoms. But this thought does not follow from the conception of positive freedom which we definitely need to fully define what freedom really is. No educator decides to offer a different kind of curriculum, no teacher decides to offer a different method of learning, no parent decides to look for an alternative. In such a society not only no one will care about any liberties, but liberties also would be totally irrelevant.