We will learn how to play Aura Lee
Let's take a look in 1st bar:

1. Look at the two F notes (see red circle in the screenshot above). All are in crotchet.
2. Play F note twice
3. Look at C and E (see green rectangle in the screenshot above). The interval is second.
4. Play note C then E
5. Play all 1st bar notes

Second bar:

1. Look at the same note G (see blue circle in the screenshot above) But the 1st G is crotchet and the second G is minim.
2. Play both G notes
3. Look at D (see green rectangle in the screenshot above) and play it.
4. now, play all notes the 2nd bar
5. Play all notes in the 1st two bars.

Third bar:

1. See three first notes: FED – it's descend notes so just play such as you play the descending scale. (see the black arrow in the screenshot above)
2. see the two last notes: EF – it's ascend notes.
3. So the motive in third bar: descend notes and ascend notes.
4. Play all notes in third bar

The second phrase (bar 4-6):
It's the exactly same with the first (strictly repetition). So just play the same way as you play in the previous phrase.

Now, you can play "Aura Lee":)