No opening always leads to an open position.
1.e4 can lead to an extremely closed position at times and 1.d4 can blow wide open, even though both are stereotyped to be the opposite. Depends on both what Black and White play that determines if the position opens up or not.
Can you list a few openings that result in and open position, is flexible, has strong attacking chances early on, and don't have too many variations to study?