Using custom fonts
If you want to stand out from the rest. I strongly advice you don't overlook your typographic choices.
Typefaces to a webshop is the equivalent of the salt to the avocado.
They are small yet meaninful choices that one should keep in mind during the design period. If you already have a store and you want to upgrade it a notch, new types can feel refreshing.
Here's some of my favorite free fonts from Google Fonts.
Sans-serif:
Headings and big titles: Muli, Monserrat Bold.
For general text and paragraphs: Roboto
Serif:
Headings and big titles: Crimson Text Bold, Lora.
For general text and paragraphs: Spectral
You can find these while customizing your theme under Theme Settings > Typography in all of Shopify free themes.
If you are feeling like spending some earnings, these are my all time favorites from well-known type designers and award-winning studios:
Canela by Miguel Reyes from Commercial Type
Have trouble deciding? Checkout what’s trending in type according to Jeremiah from Typewolf.
Now to the point...
How to install a custom font to your current Shopify theme
Owning the font
Once you have your selected font as a file on your computer.
Convert to kit
You proceed to convert the files (.ttf or .otf) into a Font Kit using this tool:
3.- Upload the fonts and style you want to use, for example: Canela Display and Canela Display Italic
4.- Select Optimal, the second option or while using Expert, make sure your files are being converted to ALL of these four extentions: .ttf, .woff, .eot, .svg - Once they have been processed, click on: Download your kit.
Once on your computer, unzip the folder.
Adding to Theme
You first have to download your theme. Adding these files.
Move the font files over to the assets folder of the unzipped theme (do NOT add a sub-folder to contain those
Source:
https://help.shopify.com/themes/customization/fonts/use-font-face-fonts