Using the Present Perfect with never is explained on Should I always use the perfect present, when the sentence uses "never"?
In short, you could say:
When I was in Paris, I never learned how to say "thank you" in French.
I have never learned Spanish.
The second sentence means I didn't learn Spanish in the past, and I have still to learn Spanish nowadays.
The first sentence is referring to something happened in a specific moment in the past. I could have learned how to say "thank you" in French later, or I could still not know how to say "thank you" in French; the second sentence doesn't say anything about that.
The Simple Present should be used for something that keeps happening. Imagine I have the habit to say something I should not say, and somebody get angry with me for that reason. I could then say "I never learn to keep my mouth shut."
Other examples could be the following ones.
I never learn those speeches of Hamlet.
I never learn from my mistakes.
In the last two sentences, the meaning of learn is different. In the first one, it means "to study and repeat something in order to be able to remember it"; in the second one, it means "to gradually change attitudes about something to behave in a different way."