Header and Tagline Disappeared

Over the last month or so, my header and tagline are no longer showing on my site [https://newdispweb.com]. There’s no rational reason for this to happen. I’m using the PINBOARD theme. Yes, I have left posts on their support section, too, but haven’t gotten any answers so far. They show if I go into Appearances Header, and they show on Settings General. But not on the site itself. I wanted to try another theme, but without taking this live site down to do so. I tried a plugin for such matters, but couldn’t quite get it. Finally, there are so many themes in WP.COM; can they be transfered to WP.ORG, or how would one go about pulling one from there? The selection seems much more limited on this side.

Thanks in advance for your answer.