I didn't see Star Wars on its opening day. I forget why, but something else was on my schedule. I saw it the next day and stood in line for something like two hours in Times Square for the privilege.
Star Wars opened in New York City at the Astor Plaza theater, on 44th Street, just off Broadway. It was part of a then fairly new entertainment complex. The entrance was at ground level...and on the second floor there was a huge Broadway theater, the Uris (now renamed the George Gershwin--I saw Annie there some years later). The Astor Plaza was in the basement...and it was huge. At the time, it was still a one-screen theater, so you can imagine what it felt like to see that opening scene of the ships coming in over your heads on such a viewing surface.
In those days, theaters still had "continuous showings," admitting audience members throughout the screening, so it was possible to sit through two screenings for one ticket (which I did). Star Wars ran at the Astor Plaza for more than a year, not finally closing there until July of 1978. In that time, I probably saw the film another seven or eight times. That makes me a piker--I know people who saw it at least twice a week in the first summer.