The question “what am I” is the most important avenue any sentient being can enter. It is not a question we can currently answer but we have been trying for as long as we have existed.
The first difficulty is that this is a true “rabbit hole” and once entered you are unlikely to emerge or find any definitive answer. Because the answer at present is “I do not know”. Even for that unsatisfactory conclusion, you have to take a detour down every possible scientific avenue of enquiry we are currently pursuing or have ever pursued.
The questions which naturally follow from this one deseptively simple enquiry do not end. At the macro level it inevitably leads to the BIG question: “what is reality”?
Until and unless you discover the nature of reality you will be hard pressed to try and answer the much smaller question “what am I” since it must be self evident that we are a mere subdivision of reality.
Unless you are a single, lonely solipsist.
So you have to take in physics and its derivatives chemistry and biology. Not on a professional level but as that of an enquiring layman. You have to consider cosmology and particle physics. You need to know what our current state of knowledge is. What is our universe? How big is it? What is it made of?
You need to know that we are made of the same elements as everything else in our universe and that all that “stuff” out there (and in us) was created within stars.
You need to consider “consciousness” because that apparently distinguishes us from the vast majority of “stuff” out there. It allows us “self awareness” which can usefully be defined in this context as the ability to ask what we are in the first place!
My current reading is Our Mathematical Universe by Mark Tegmark . It is fascinating and easily understood by the layman and those not versed in mathematics. It is well suited to someone of a more philosophical than actual scientific bent.
It is telling me that I am a mathematical structure and so is the rest of reality. It is one man’s theory of the ultimate nature of “what is”.
It is one of numerous such books I have read on my journey and there will be a great many more.