The Government has created this booklet for school leavers - https://yourcareer.gov.au/media/xlcbghjw/school_leaver_information_kit.pdf
Cover Letters are letters written to your protentional employer to tell them why you would be most suited for the job. In your cover letter you should introduce yourself, explain why you are the best candidate for the position- by stating your skills, summarise your points and request a follow up.
A resume is a document that contains your past work experience, training and skills.
Below is a blank Resume and cover letter for you to use as templates.
exemplars can be seen here- https://jobsearch.gov.au/jobsearchtips