I'm not a teacher, but even native English speakers don't like these examples. Past perfect is generally used AFTER the conjunction "because," since whatever you write after the word "because" happens first. Confusing enough? For example, "I WENT to the store because I HAD EATEN all of my food." Although I mentioned it second, I "had eaten all of my food" first. The cause must happen before the effect, therefore the effect shouldn't be past perfect. You could change your sentence to say "I had got up early before I went to the station," but that would change the meaning. For what it's worth, in spoken English you can use the past perfect in your example and sound perfectly normal. (Note: Americans will more often say "had gotten," since we tend to use "gotten" as the past participle of "to get")

Don't be confused by the "had" in "had to go"; that isn't a marker of a pluperfect construction, but means something like "was obliged to go" or "needed to go" in the simple past. Likewise, "got up" is in the simple past.