Landing Page Video Frame Size

How I change the video frame size in a landing page?

My landing page has 2 sections. Section 1 is the video element. Section 2 is a calll to action button. The landing page does not show both sections on the screen. Have to scroll down to get to the call to action button. Want to have both the video and call to action button fully visible when the landing page loads and the video plays.

Any pointers would be greatly appreciated.