how do you make a personal statement?

This can also be known as a "career objective statement" and can include things such as why you are interested in that particular career path, if you have any experience, what you intend to get out of it in the long term etc. Make sure it's brief though, just a paragraph like you said. Mine goes like this:

"I have always had an interest in administration and I would like to continue working in this area. With two years’ experience and my Certificate III in Business Administration, I am a keen and enthusiastic worker who is always eager to learn. I would like to take this opportunity to broaden my knowledge and skills in a new working environment."