@France11 Carefully check the job tasks required for a successful skills assessment for Advertising Specialist and for Marketing Specialist, then have yourself assessed for the occupation which most closely fits your work experience. The advertising or marketing medium doesn't seem to matter much in the assessment, what seems to matter is whether or not you are doing the tasks that Vetassess requires for those occupations.
Both Advertising Specialist and Marketing Specialist aren't eligible for a 189 visa. You have to check which states sponsor your occupation for 190 or 491 visas. 491 visa is a provisional visa with a guaranteed pathway to a PR visa once you satisfy the visa conditions.
You can try applying for jobs online but most employers prefer to hire someone who already has working rights here. This is because it's expensive to hire overseas workers. The employer will have to do job market testing to ensure no one here is qualified for the job opening and they have to pay a levy.
Given your age and number of years of work experine I suggest you try to get a 190 or 491 visa.