Help ^_^

Another essay to write for school.. >_<

This is the topic which I chose -

Nurse or trainer

Paragraph one - support ( I need to write about trainer )
Paragraph two - support ( I need to write about trainer )
paragraph three- against ( I need to write about nurse )

So what to write about on paragraph one , two and three?

I'm thinking of writing about why I want to become a trainer for paragraph one?
I don't know what to write about for paragraph two.

And for paragraph three -
On the other hand, I want to be a nurse because I like to help people.....