English Translation
People were lined up around the block waiting for the theater to open.
Schlange stehen → to queue
https://en.wiktionary.org/wiki/Schlange_stehen
https://de.wiktionary.org/wiki/Schlange_stehen
At first I was confused by the first part of this sentence until I realised that there was probably more than one word making up the verb (I understood all of the individual words, but they seemed to be just thrown together in a random order).
N.B. On the Tatoeba page for the German sentence, there’s also the question of what form öffnen should take.