I'm in the process of editing a music video for a friends group in school (which limits my access to vegas). And I want to have the "Old Flim" filter at the begining of the video and fade out about 20 secs. into it. How do I "Paint" the filter so i can do this.
Not sure what you mean by "paint" but keyframes will bring in and out the filter as you need it. You'll probably do best to either put the effect on as a track level effect, or make sure that it matches all the in/out points of individual events if you drop it on the opening and ending events.
Keyframes will define the behavior of the filter at specific moments in time, as defined by you.