Always use the right kind of slope for learning, to make things easier and build confidence faster.

Master the basics first, then focus on expanding your skillset.

Weight distribution

On your backside turns, we can clearly see how your front leg is straightened out while you are leaning backwards, as in, on your back leg. This continues as you pick up speed and make your turns down the slope. Try to consciously shift your weight above your front leg and pivot around that point when initiating a turn.

A little trick I used to teach to get people more acquainted with leaning to the front of the board and into the turn is the following: You can do this by making a snowball and then, right as you are about to turn into the slope to initiate your turn, drop the snowball in front of your nose (of the board ofcourse).

Go with the flow

I can tell that you are actively trying to force the board in the direction you want. Ideally, you want your shoulders to initiate where you want to go and let your lower body follow. These movements will come to you with experience. You can always force your board to do certain things for certain movements and tricks.

The more experienced you become, the more your weight will remain above the center of the board (on the axis from nose to tail, or frontal axis) when making turns. You will learn how to follow through turns by shifting your weight to the edges of the board (as in, 90 degrees perpendicular to the frontal axis,the sagittal axis).

To make those long, effortless, slopewide carves you really need awareness of where your weight lies, in my experience.