First, welcome to the site.
Second, I strongly recommend browsing this thread:
Third, included in that somewhere is a link to a video titled "don't talk to police":
It's long but VERY useful information, coming from both a law school professor and an ex-detective.
Watch it, then put it on your calendar to re-watch regularly.
Fourth, the group called Flex Your Rights has its own website http://www.flexyourrights.org/
as well as a channel on youtube. Highly recommended watching their videos too.
Fifth, ask leading OCers in your state if you live in a "stop & ID" place.
If not, unless the cop has reasonable articulable suspicion (RAS) of a crime, you don't have to interact with them at all, even to stop when they say they want to chat.