Agree with the other post. In addition if the ear pieces are shoved in too far you can suppress the sound.
Close your eyes while listening, it helps to focus and tune your hearing. Try to identify breath sounds first, place the scope over the upper back area and listen to inspiration and then expiration, breath in, breath out. When you can distingush breath sounds, tune them out and listen for the heart sounds , however, you will have to place the scope over the anterior chest around the nipple area. Listen to your guts (abdomen, belly). Listen to yourself, listen to your husband and try it out on the kids.
If you, your husband and your kids are young and without health problems you are probably listening to normal sounds. You will learn normal sounds first. After that you will eventually learn through experience the abnormal sounds. The more you listen and think about the mechanics of what you are listening to the more you will learn. Practice, practice, practice.
Most of our family members have survived nursing school
and been our practice patients.
Have fun and welcome to nursing school. Good luck