Welcome to the forum!
Everything you need is in the Editors Depot. There's a link at the top of this page and it's worth spending a little time exploring to see what's there.
To learn how to make scripts (its dead easy, don't worry) read Johan Gustafsson's Scripting Tutorial and snYpir's A Friendly Intro to Code Snippets.
To see the switchmove/playmove animations, find the little demo mission that ponq and I made. There is also a helpful reference list of the animations. There are several versions of sitting down, so experiment till you find the one you want.