As you know, it is possible to play the same note in more than one octave. Here is a new C note played on the A string. It is played with the 2nd finger slightly lower (back towards B) from where you would place your finger for a C# note.
This C note is written in the third space of the staff.
Play this C note with your 2nd finger on the A string.
Now try this example which combines the new C note with other notes you know.
This G note is written above the top line of the staff.
Play this G note with your 2nd finger on the E string.