How to create this effect + tutorials?

I am looking to add a scroll feature where one section appears fixed and the others scroll over top, like the example below:

On my Press/Booking page, I would like the top video section to be fixed so the rest of the page can scroll over top. What type settings should I use to get this effect? And are there some tutorials that explain about this section scrolling over section look? Also interested in tutorials about sections scrolling “past” fixed background images, like this:

Here is my site Read-Only: