I got my feet wet riding my road bike on a route that my LBS pointed out to me. They use it as a training ride. It was marked and largely out in the country. I lost count of how many times I did it when I first started riding. It helped my comfort level tremendously in that I didn't have to worry too much about traffic but still had the experience of riding on a road.
I would start doing group rides when you feel stable on the bike and can hold a steady line and have a basic understanding of traffic laws and hand and voice signals. I would avoid group rides for the time being that involve pace lines. If and when you do join a group, don't be afaid to ask lots of questions and to identify yourself as a new road rider. Check with your various local shops to see if they offer a ride for beginners.
Good luck and have fun!
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher