What would be a good introduction for an informative essay about the career you would like to have in the feature? Or a Main Idea?

Opening with a statement about the career you would like to have ("In the future, I hope to work in the field of computer science,") and continuing to explain why ("because computers can be made to do amazing things, and I have a few personal goals in mind,") and perhaps giving an example of an inspiration for that field you compare yourself to ("like Terri Thompson, who admire greatly.") would be a good place to start.