There are three notes to learn on the second string, the open B note, the C note on the first fret and the D note on the third fret.
The open second string is a B note. This B note is written on the middle line of the staff.
Exercise 91.0 introduces the open B note.
It is good practice to reverse the order of your right hand alternating fingers as shown in the following exercise. Practice all the following exercises and melodies both ways.