So in the link you posted, if you scroll down a little bit you'll see HS2 Guides and a spoiler tag, that'll take you to most of the resources you need. I'm used to koikatsu but it should be the same commands in HS2. So once you open studio neo, press F1 key to bring up a list of all the plugins you have installed. From there you can click through them to see shortcut keys and adjust settings. For the 2 you're specifically looking for, F11 will render the scene and by default it will be in whatever size the window is and the background will have transparency applied. To open the settings for the screenshot tool to adjust the size of the render, background transparency, etc I have it set to F12 which I think is the default but I can't remember now if I changed the binding. For video, there are more advanced ways than this but the best way to start is to use the image series recorder plugin which the default keys are left shift + R. It's pretty self explanatory once you bring it up, just set size, framerate, etc and click start.
