How to set up HTTPS WordPress from Install Step?

I tried posting this in comments but it kept stripping some of it so I figured using this I can be sure my response formats correctly…..

Mixed-content errors can be a PITA to run down…try viewing the source for any page that gives that warning and search for instances of http: – often it’s in template files, like the header/footer, could be a hard-coded link like "itemtype="http://schema.org/WebPage" that just needs the ‘s’ inserted, sometimes it’s URLs within post content that call images using http: instead of https: so you might have to do a search/replace on DB content…..