Need help with title and tagline.

Hi there!
I have a blog https://www.fantasticfoodworld.com/blog, we had some designers help us set it up, but I have now discovered that because it has a custome made headline and no title and tagline, the blog comes up in searches as having no title. If I so write the title and tagline it will just be written on top of the custome headline.
How can I make sure that I have a title and tagline for SEO purposes, but not showing on my frontpage? My theme is bluesky.

Oh, also realized that if I even put a title and tagline in, it still comes up as no title and no meta tag description in search engines. Anyone now what can help?