It's a downer not being able to decipher tabs and timing. Classical piano never prepared me for this. -----------------------------------------------------------
Shoot, the banjo is pretty simplistic compared to the piano!
In your case you might not want to bother with tab. Give yourself some time with the basic strum and then take what you already know from the piano and apply it to the banjo. Since you can already read music you'll be able to visualize the rhythmic stuff a tad easier than a tab-monkey - and then you can mosey on over to the .abc tunefinder and have a blast.
Don't sweat it. The great thing about the banjo is that everybody has something to add to the mix. Your background in classical music could lead to some interesting ideas like a string band playing in harmony rather than everybody just pounding out the melody line. Your previous training is an asset. Celebrate that.