You can change the fonts and colors of the blog title and description in Theme > Customize > Advanced > click on "Links" to expand the dropdown > select "Blog Title, Description and Logo".
Blog title and description
- Go to Layout
- Open the Header widget
- Change the title in the "Blog Title" box
- Change the description in the "Blog Description" box
Upload a logo
- Go to Layout
- Open the Header widget
- Click on "Choose file" and upload the logo from your computer (don't click on "Shrink to fit")
- You can check "Instead of title and description" for Placement (or "Have description placed after the image" if you want the tagline to be visible below the logo)
Some tips
- Blog title — depending on how long your blog title is, you might want to adjust the font size on desktop + mobile; go to Theme > Customize > Advanced > click on "Links" to expand the dropdown > select "Blog Title"
- Logo — to make sure your logo will be displayed beautifully (and not blurry!) across all devices, the width should be at least 1000px (height doesn't matter)
- Logo — crop all the white space from your logo, otherwise it will add too much unnecessary space once you upload it