If you want to the infinity room most days there is a line before they. You can only get tickets in person and it's first come first serve. For general admission during the week there is no line usually but the weekend can get hectic
If you want same-day tickets you stand in line. Best time to do so is 10:30 when they first open. Otherwise, you could be waiting up to two hours. Online advanced tickets are less time consuming.
Thanks! Your answer is awaiting moderation.