The note C is written in the third space of the staff. Notes written above the middle line of a staff usually have their stems going down.
The fingering for this C note is the same as that of middle C. Like the note G, you will once again need to use more pressure to sound this new C note correctly. Practice alternating between this C note and G, and also middle C as shown in the following example.
Here are two more piece which use the new higher C note. The first one is a duet which features slurs covering groups of notes.