Welcome Mickey, There are some good suggestions above. I would have to ask what genre of music are you most
interested in? It might help you early on not only to be familiar with a song but also be energetic to want to learn
and play a song you like. If country is ok for you I recommend Waylon Jennings old song "I don't think Hank done
it this way". A two chord song with a very straight forward 4/4 timing, easy to strum. Waylon recorded it in B and E
I believe, but, you say you'd like to stick to G-C and D for now so try the song in the key of G with a C.
Hope this helps. Mike
Our intuitions serve us well