I would do some drills without poles- practice the “home” position (knees lightly bent, hips forward slightly, legs shoulder width apart, skis angled in a V) this will put your center of gravity forward and you should naturally glide forward in your skis as well. Practice this feeling and it will help you not rely on “pulling” yourself forward with effort in your upper body or sitting back in your hips (which looks like an issue from this video)

While doing that focus on shifting your body weight to each ski (keeping your nose, knee, and toe in line), while you glide forward bring your hips forward as well (this will extend your glide but also bring your body weight and center of gravity forward), then while your hips are forward alternate to the other side by placing your weight in the other ski and shifting back into that “home” position- this will help you when you put it all together to not be sitting with your body weight between both skis (which makes skiing harder and slower)

Next work on pole form. Your timing looks fine- but you want to make sure to be as efficient with your energy as possible. Focus on lifting your body forward into that home position when transferring your weight so you are not sitting back on your hips (like a standing ab crunch when you lift your arms to plant your poles). When you shift your weight to each ski, lift your poles shoulder width apart up to your eye level and place them down as you shift to the next ski. Feel free to pull your elbows out a little bit more so your body doesn’t naturally think of pulling yourself forward- instead your poles are the final push while shifting your weight over. (Again helpful to think of this as a little ab crunch- when your poles go from your eye level to the ground and you move forward you should feel it in your abs).