How I can change "handles" rotation individually in animation editor

hello. I’m trying to make animation. Due to new curve editors, It’s much harder to me to remove “bounce” effect, where character moves 2 times further then needed. Also, I trying work with this handles-levers, idk how to name it properly:
image
And I notice, that sometimes I may change only 1 of them, without changing another one, like this:
image
Also, there’s 2 white handles.
Can someone say me, how I can change these handles orientation like in second picture, not moving both of them?