doesn't sound like you goofed to me... just make sure your water is at the right temperature, you have good flow, your salinity is stable, and you're lights are on during the day and you should start to cycle.
You did fine. Goofing would have been putting the rock in before the water . Now just sit back and watch the ammonia/nitrite/nitrate spike (in that order). Once those are all back to zero, you can start adding a little bit of livestock (I'd start with a few snails first).