Aura Lee introduces the music repeat sign (Bar 4), which consists of a thick and thin line, with two dots placed before them. It indicates a repeat of the section of music which has just been played.
This song introduces lead-in notes, which are notes occurring before the first complete bar of music. These notes should be played on counts three and four of a count-in (as indicated). You will notice that the final bar of the song contains only one half note (two counts), which acts as a "balance" to the lead-in notes. This is quite common, but does not always occur. Lead-in notes are sometimes called pick up notes.
Fingerpicking is mostly played on acoustic guitars. If you are playing in public, at some point you will need to amplify your guitar.
The most common way of doing this is to get a pickup fitted to your guitar and plug it into either an acoustic guitar amp, or the PA system used by the singer. There are many pickups available for acoustic guitars and most can be attached for a performance and then removed until required again.