The first exercise is four bars long. The note E is played on the first beat of each bar. Each E note is a whole note, therefore it lasts for the duration of the entire bar (4 beats).
When using your fingers to pick the strings you must alternate your i (index) and m (middle) fingers when playing single melody lines. Try playing the previous exercise again but this time use the i finger to play the E note in the 1st and 3rd bars and the m finger to play the E note in the 2nd and 4th bars.
The rest stroke: After the first E note is played the i finger should rest on the second string until the m finger is ready to pick the E note in the second bar. The i finger should move from the second string at the same time the m finger picks the E note, which then comes to rest on the second string until the i finger ready to play the E note in the third bar, and so on. The fingers should give the impression of 'walking' across the string.
The free stroke: The free stroke uses a similar walking motion except the fingers are slightly more bent and move in a more circular movement.