Hold water, don't push water
This is how to increase distance per stroke
Swim past a stationary hand
If you only hold water in front of you, and don't push water under you, you will move forward much better, with more distance per stroke.
Hold water, then let your hips do all the work.
The best way to learn freestyle is to swim backstroke and lots of it. In backstroke the option of pushing water under you disappears, you can't. Now you have to hold water. Now you have to develop balance, posture, and alignment. Now you have to rotate your hips quickly.
The less you move water backward, the more you move forward.
If your hands slip backward, upgrade your balance, posture, and alignment
Swim with more distance per stroke, not faster strokes, more distance per stroke.
Hold water and swim past the catch.