How to scale vertices selection? So I'm watching this tutorial: https://www.youtube.com/watch?v=CVPcT0dJmoY

and around 41:44 he selects only a small part of the circle, How does he do that?

To clarify:

That circle, how does he create that? Whenever I try to do what he's doing, It does this:

It affects the whole circle, not just a portion of it.
When you have Proportional Falloff Editing enabled, you can adjust the falloff size with scrollwheel while moving/rotating/scaling. As it is affecting the whole mesh, it seems you have the falloff size being bigger than your view, so just scroll down while editing. The falloff size can also be edited after action in bottom of toolbar (hotkey T) or by hitting F6.