Is this able to do either of these 2 things? if so how?

1- templates for embed youtubes?

want youtube videos layout in a grid like pinterest

auto-play upon hover

if template can embed videos from anywhere else not just youtube like vimeo that is also good

2- Making helpful resource site - what's good templates for this?

screenshot on left side

link + explanation on right side

only 1 of the helpful sites would show up at once

press right arrow -> to go to next helpful site

guess google slides or other things would be better for this?

1. what are the steps?
2. does it do it by default?
3. is there a helpful template for this?

Yes, there are no restrictions that would prevent this, apart from browsers moving toward blocking autoplay of foreground videos. You'll just need the JS, HTML, and CSS for 1. The videos must be implemented as background-elements, otherwise it's liable to break quite quickly when browsers' catch up.

The concept is relatively simple with modern standards (CodePen). For the grid, there are various layout-methods you might want, all of which are solved by the Grid or Flex CSS Modules.

For 2, all of this can be solved with Reveal.js, for example using the Presentation-plugin.

there's no templates ?

looking for easy simple option, what is this mainly for if there's no templates that other things have ?

I am not aware of any pre-built templates/extensions for this. This thing is mainly for managing content and rendering it in an efficient way; there's very little feature-overlap for niche-cases such as this across Content Management Systems.

The resources I linked demonstrate how to do this easily. Like anything, it does require implementation in a Theme or a Plugin. There are some Themes that do use Masonry-layouts, but it's not common to autoplay videos as well.