For undergraduate admissions, there is no strict format in which you need to write a college application essay. I have seen people writing essays in the form of a monologue (expressing their thought processes on a particular subject matter that ultimately expresses their personality); some choose to write it as a conversation between two people. Some of the essays are really objective (which is I think the usual way of writing an essay). I do not think it matters as long as you can stay within the word limit and succeed in proving your case or effectively expressing yourself. I do think that the more creative approach you take, the better it is (just my opinion).
These are some samples: https://www.internationalstudent.com/essay_writing/college_essay/
But when I applied, I had not looked into samples and just written my own story. And I think it is similar case with a lot of my friends too. So when it comes to essay, being personal adds value to it. “Your essay should be a reflection of you” so searching online to write essay would not help as much as writing it on own accumulating inspirational moments that drive you for your goal in life.
Requirements and expectations vary from universities to universities and programs to programs. If you are talking about undergraduate levels answers in THIS page might help you.
For graduate studies, you might have to show research experience, internships, or even work experience depending upon the programs. I would recommend you to research more on the university and programs that you might want to apply and then prepare accordingly. Here are some examples for grad essays.