This is a good starting point for who doesn’t familiar with standard notation and wish to play Classical pieces.
The first music I studied for guitar included folk songs such as Freight Train. Later I tried my hand at classical music. This was a painful experience. Despite much persistence I was unable to read music. At the same time I was easily learning folk music from tablature. As an experiment I translated Étude in D to tablature. Within a month I was playing the piece fluently.
Étude in D is still one of my favorites. Another song I especially enjoy is the Gymnopedie, by Satie. I’m afraid I played this piece obsessively while I was learning it. The other pieces are fairly easy, as I never progressed past the advanced beginner stage. If you study any songs, and want to bring a smile to my face, send me some email. If you can read music, or would like to learn, I recommend Frederick Noad’s book