A Personal Essay should actually show who you really are and what is your real background that led you select that career. Nonetheless, here's an example on how you could do it:
Hello! My name is Mary and I am from California.
I grew up with a sick sibling that needed support to move, so over the years I developed a great interest on helping others to get well in the most professional way possible, and reading a book on Medicine I found out that I wanted to be pharmacist so I could help others to feel and get better.
At school, I was the first in class while I volunteered as a secretary on the my aunt's office, who is a doctor, to learn a little about Medicine and the sick body. When the time came, I chose Pharmacy as a career at the University of California. There, I fell in love even more about Pharmacy and I developed a deep wish for research. So, I worked along Dr. Stuart in the search for the impact of specific medications on people. The results were published on the university's journal.
I look forward to keep on research on the impact of the high use of medications in the human body and contribute with science, for that reason entering to this Doctor of Pharmacy degree would relate deeply with my professional and personal goals.
Thank you!