In the midst of wrapping up its fifth successful season, Ballet Nebraska (balletnebraska.org) is pausing to take a look back.  The ballet company will host a premiere party April 16 for Lance Glenn’s film It Starts with a Step: The Story of Ballet Nebraska. The behind-the-scenes documentary uses interviews and contemporary footage to follow the company’s intense first few months, leading up to its October 2010 debut performance at Omaha’s Orpheum Theater.  The 7 p.m. premiere party, sponsored by Aksarben Cinema, is free and open to the public, but requires making online reservations by April 13 at balletfilm.eventbrite.com. In addition to the screening, the event will include a question-and-answer session with Glenn and Ballet Nebraska dancers, followed by a reception with light desserts.