A duet is a piece of music played by two instruments at the same time. This may be two recorders, or a recorder and a guitar, or a piano and a singer for example. The following example is a duet for two recorders, using the note G along with the other notes you already know. The top line is for you to play and the bottom line is for your teacher. When you get to the end of bar four, remember to look at the top line of the second system of notation for your next bar rather than the bottom line of the first system (the teacher's part) Learn your part well so you don't get distracted by the other part. You can also practice your part along with the CD.
There are no breath marks in this piece, but there are several rests. You can breathe anywhere a rest occurs in the music. This is a good general rule to follow.
Here is another example which makes use of the notes G, A and B. Once you can play a melody, try playing it from memory with your eyes closed. This will help you learn the fingerings of the notes and also make you more aware of your tone.