If you're interested in learning how to read music notation this lesson is a great place to start. Ways to learn to read traditional score might start with a C note because that suits piano quite well. Also the lowest line of the traditional score staff represents an E note so many lessons may start there. This is all fine and good. We're going to do something a little different - because the lesson here is still very close to beginner material. If you look at the music staff in the diagram below (it's in the bottom right hand corner) you'll notice there are no sharp or flat notes, all notes fall in a nice sequence in the spaces between the staff lines, and no notes exist outside the main staff area. So, it's a pretty easy way to learn three notes on a musical staff. If you play guitar or keyboard you can look at where those notes are on your instrument and play them.
The exercise below shows how to play those notes in a nice easy pattern. It's F-A-C-F. The top staff is for standard instrument pitch, and the bottom staff is for bass instruments. The score below is basically for piano. The first bar plays F-A-C-F in a middle register (pitch). Play that with your right hand. The second bar plays the same notes in a low register. Play them with your left hand. If you play another instrument you either swap between high and low notes on your own instrument, or just repeat one of the bars over and over again.
As you play look at the music score. It's even a great idea to say the names of the notes as you read and play them.