I was just wondering what exactly do I write in the beginning of the personal statement where it asks us about our goals and why we want to do tertiary education and future career?
You genuinely just answer those questions. Why do you want to get into these courses, compared with not going to uni? What are your long term career goals? How will this course make your life better and contribution to society better? There's no right answer to this - they don't want everyone to write a formulaic answer; they want you to genuinely answer the question. You can start with "I want to..." or "I'm passionate about..." etc.
Can I add a question too - what is the point of the personal statement? If it's not a required thing for whatever you're going for. I mean how does it change things?
I hope you've read
https://www.vtac.edu.au/applying/personal-statement.htmlIt's more often used for non-VCE entry, or possibly courses with more competitive entry. It gives the admissions officers more information about you - it gives them a concept of what factors affected your scores, what other things you bring to the table, why you want to get into the course, etc. It never hurts to submit it, but if it's not listed as a requirement for that course, they might not even bother reading it because it's infinitely quicker to do admissions based on just scores (+ SEAS where relevant).