Hello! I'll try help with the introduction as I'm not quite sure how you will structure your personal statement. Now, your intro is arguably the most important part. Admission tutors have PLENTY personal statements to read and you want to STAND OUT. You want to show your understanding of what it takes to be an engineer/lawyer/architect/geographer etc so admission tutors recognise you as someone who's genuinely interested, fairly knowledgable and deserving of a place on the course over other students.
Why is it that you are applying for whatever course you chose? What does it mean to study this course? What is it about this course that interests you?