So, if I'm seeing this correctly:
Hank creates Pym Industries, invents the suit back in the 60's.
At some point, there's a (hostile?) takeover of the company, Hank gets shut out, Darren Cross assumes control.
Pym's daughter works at Pym Industries under Cross.
In order to get the suit back, or to get the technology out of Cross' hands (who, I'm assuming, wants to weaponize it) Hank seeks out a thief. Relating to the father-daughter relationship that Lang has, and seeing the good in him, he recruits Scott to help him.
The heist goes off at Pym Industry, with Hank planing, Scott executing, and Hope as their inside man.
Most of the backstory is fairly textbook. Depending on how the heist goes, this could be pretty fun.
I will say that I've been a huge fan of almost everything Marvel's put out to date. Still, I did find this trailer pretty bland. Would be foolish to judge the movie based on it alone, especially with the people involved.