Yeah offset gets rocky at the start but it does take a while. First, adjust your in-game offset setting (START button).
Second, switch to an in-game VEFX such as Compressed (Green)
Third, disable all computer sound effects such as Dell Audio or dtsX effects as they can distort audio quality
Forth, use a wired keyboard to minimize input latency
Fifth, use as high a display rate as possible, 120Hz if possible. You should aim for 60fps min.
Sixth, lower your green number via in-game setting and floating number adjust (I play at 300 atm)
Seventh, and above all, just git gud. Seriously, more you play, more you will match the timing. Soon enough the As and AAs will come your way.