I am so sorry for your loss. I agree with a lot of what was said above. However, if you want to write about your father, here’s a different approach maybe…
Start by describing an interaction you had with him that taught you something something specific that paints a picture of your child/parent relationship. It could be teaching you a skill, or demonstrating his values in a specific interaction in a way that made an impression on you…then go on to describe how the skill/values/whatever you learned from him play out in your own life…how do you bring your own gifts to help people in your community grow and learn…just as he helped you. Then talk about how applying the values he taught you have given you a deeper appreciation of him as a person. And then, in the end, reveal that he passed away after his battle with cancer. It’s almost a shocking “reveal” at the end (a-la Sixth Sense). I hope that analogy doesn’t offend - I don’t mean this as trite. But rather, it can make the whole essay more memorable because the ending is not expected - and being memorable is important since AOs reach thousands of essays. Finish with an example of how you are and will continue to live out his legacy. So the essay isn’t really about his death, but it is about him…and mostly about you. Best wishes to you. And again, I’m so very sorry for your loss.