The content you create should be shared on the social networks on which you're active. (And if you're not active on any, this is one of the reasons to get started.) Moreover, Google's algorithm considers social signals as one of its most important ranking factors -- socially shared content is a vote of approval, or at the very least importance, so it makes sense Google would consider it when deciding whether a post should rank well in organic search.
Do research about the brand before applying to jobs. If you find a copywriting job you want to apply for, avoid just talking in vague terms about your copywriting experience. Look up and see what it is you might be writing about for them—this will not only help you create a more detailed cover letter, but it will help you in an interview to show that you’re truly interested in the job.
Your specific needs might vary -- for instance, perhaps you need subject matter expertise in your writers, or coding experience from your long-form content creators. Or perhaps your titles differ, and your "content creators" are actually "content strategists", or your "social media manager" is really a "specialist." Make edits as you see fit, but these frameworks should be helpful in getting you started if this is your first time hiring for any of these positions.