From your initial explanation it sounds like you have a copy of Episodes 4-6 before the Special Editions.
To be certain, what types of packaging did they come in? Also a quick thing to check is on the Episode 4 tape, at the beginning (before the crawl) does it say 'Star Wars' or does it say 'Star Wars : Episode 4 : A New Hope'?
What aspects of the movie we're unfamiliar to you and your friend? I'm guessing but your under 20, right?
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