Play Queens Gambit. I can't say its easy to study because there is tons of theory in the Slav and QGD. Also if QGA, you'll find a clear initiative for white.
What is the most forcing opening for White?
Well guys, here a programmer and chess player in free time. I've done a script that filters stockfish moves with some parameters and counts the number of "good responses" for black against each whites first move with some depth. Turns out that 1.NC3 is BY FAR the most forcing move for White to begin with.
Sorry, I take back what i said before, it is probably the dutch gambit
I think that this is actually the Danish Gambit.