Not the easiest thing to do with what the video shows but I'll take a stab at it.
First, since you're holding the camera to film yourself, it isn't a true showing of your skiing. It is best to see the entire skier and have some reference of the terrain. Looks like its a groomed green trail.
Based on the way your skis are twisting side to side independent of each other and the fact your knees are behind your toes the entire time, it looks like you're in the back seat. Your skis (for the most part) should act like the front wheels off your car; independent suspension but they turn at the same rate at the same time. This isn't an absolute truth but from the looks of the terrain in the video, I would expect it there.
For your body position, get more pressure to the front of your skis by trying to get your knees to touch your toes. I know it isn't possible but is a directional goal or target. The angle at the front of your ankle, back of the knee and front of the hip should be close to equal. This should put your shin and spine parallel and femur perpendicular to them. I hope that makes sense.
it also looks like your stance is a little wide; not a lot but could come in some. Your feet should be no further apart than your hips. This will help with your skis moving as a team too. Your ankle, knees, and hip should be stacked.
the good news is you've done pretty good for teaching yourself. You're maintaining control, are linking turns and can stop. This isn't the easiest thing for people to pick up on their own. Aside from the fact that I'm an instructor, I would urge you to take a lesson or two because you will have more of the mountain opened to you. There is a big difference between getting down a trail and skiing it well. This is a life long pursuit and the better your foundation skills, the more fun you will have.
keep at it and see if you can get someone else to video you showing your entire body.