Pitch is how high or low a sound is.
Try singing a note while holding your hand in front of you. While bringing your voice higher and lower, try having your hand follow the pitch up and down. Try singing the highest pitch you can (with your hand as high as you can reach) and singing the lowest pitch you can (with your hand near the floor). This is one way you can explore pitch using your own voice.
In Music Blocks, we have many different ways to represent pitch. For beginners, we want you to focus on two types: Solfege and Alphabet. When you pull a note value block from the palette, it has a solfege pitch block by default. Click on the pitch name part of the pitch block and try going around the pie menu and listening to the change in pitch.
Both solfege and alphabet pitch blocks have octave as a number. Higher number octave pitches are higher in pitch than lower number octave pitches. Try playing with this outside wheel to see how changing octave affects the sounding pitch.