Which Opening?

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?

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.

You can't take the easy route, you have to work hard, train hard, and study hard.

Let me list some:

Giaco Piano

Queen's Gambit

King's Gambit

Ruy Lopez

Evans Gambit

Alekhines Defende

French Defense

Smith Morra Gambit

Polish Opening

Nimzo Indian Defense

Benko gambit