Hiding Site Title & Tagline in Header

I created a custom header in PicMonkey so I could inlcude an avatar and text of my own. In Customization/Site Idenity: If I leave the Site Title and Tagline in, they show up over the custom header. I’ve read that these should not be deleted for SEO purposes. Is there a way to hide them? Side note, even if I do delete the Site Title and Tagline and/or uncheck the box for “Display Header Text”, this odd line shows up. I can change it’s color in the Customization, so I’m guessing it’s part of the Site Title…I’d like to have it go away as well.

Much appreciation for any assistance.