>>1455664This isn't technically just piano sheet music, its piano/choral sheet music.
Often times (and especially with choral music) there are different "voices" in each staff of music (the horizontal blocks). In pure choral music, this will be a soprano voice and alto voice in the treble staff, with a tenor voice and bass voice in the bass staff.
In your case, there is a unison (soprano) voice in the treble staff in addition to the piano's voice. You don't actually play the unison voice because that is what is sung.
You can tell the difference between what is for the piano and what is for the unison voice by the direction of the stem. The higher voice typically has stems going up, and the lower voice typically has stems going down. In your case, the unison voice has stems going up and the piano has stems going down in the treble staff. This won't be universally the case, especially with solo piano music.
I have marked up your image to demonstrate. The green is the treble clef, which marks the treble staff. The yellow is the unison/soprano voice, and also the melody. The pink is the piano voice treble, which should be played by your right hand. The red is the bass clef, which marks the bass staff. The crimson is the piano voice bass, which should be played by your left hand.
