I am very happy to hear that you are interested in human biology which is like you are studying about universe it’s so much to learn and practice.
Heart which is one the most imperative part of our body and the most interested thing is you can hear that sounds However, I can say you have to give more time and attention. There are lots of videos and research books which will let you dive in ocean of knowledge and found it more interesting.
The heart is a fascinating organ. One of the best resources I have used in the past is by Frank Netter. Begin your research on a search engine typing in "Netter heart anatomy." The images are very detailed and colorful to help you remember the various chambers of the heart. I would also suggest that you create a search for "heart sounds and rhythms." Enjoy!