How long should a written speech should be if you're writing about a person?

I just started my college 2 days ago(which is great :-D) so anyway my first class was Public Speaking and the teacher wanted us to pick a person,write down things such as what they like,their hobbies,are they single,etc.But what I want to know,how long is this kind of speech is usually written?Is it just like main idea,first paragraph, 2nd paragraph, 3rd paragraph, and conlclusion with atl least 5 sentences for each?Have any examples?