What are your goals? By this I mean, do you hope to simply play a few of your favorite pieces well enough to enjoy and play for friends/family, or do you want to become a concert artist, or something in between?
If all you want to do is learn a few favorites, then I would suggest finishing Fur Elise and playing it really well. If you can sight read and practice carefully, you should be able to do that. Then, pick out some other popular, lyrical pieces that are easily recognizable-such as the first mvt. of Beethoven's Moonlight Sonata, Claire de Lune, some Chopin preludes, etc.
If you want to become a concert artist-I suggest you hire a highly qualified teacher, and let him/her guide you.
If you want any repertoire suggestions, or technical suggestions for Fur Elise, I'll be glad to help. However, I strongly suggest against you even touching the Rach 3 at this point. Listen to it on a disc and enjoy it, but you'll likely only develop bad habits. If you want to learn Rachmaninoff, at your level I would suggest starting with his "Melodie" of op. 3. It is a lovely piece, not difficult-and very satisfying.