i know it's very hard to find work as a young person, especially with not much experience. what would help in the meantime while you're applying for jobs, is to find a volunteer position in the field you're looking for i.e - retail. you could look at the volunteer side of SEEK.com, or places like oxfam and charity shops always need a helping hand. a volunteer role gives you many skills you can use in any future job, and a real, reliable reference, too!
for your resume/cv, me and my friends have found that we had a bit more success when we made a broad CV that applies to any job - basically a little introduction about yourself, then your skills and experience implementing them. don't have actual field experience? you can add little bits and pieces that you've done on the side, say you write stories as a hobby, well you have editing and proof reading skills, and doing a bit of dog walking around the neighbourhood shows you can manage multiple clients in a professional and friendly manner.
i felt like you did a few years ago - i'd never had a job, kept getting knocked back for positions time and time again, but i kept persiting and didn't give up (even though i felt like nothing was going to happen) and eventually i was given a chance and landed my first job in retail. i'd done a breif stint as a volunteer at oxfam which let me bulk up my resume with a few new skills, and trawled the internet for resume templates to stand out from the crowd, which i think helped a lot.
please don't give up! you will get there eventually. it just takes time, like all things in life. so maybe for those online postings, do a generic CV and just apply, apply, apply. see what happens. i hope this helped a little!