UPDATE:
I also pasted the font-family code change within theme.liquid and now the font has been changed globally.
Anyone who is looking to implement a custom google font onto their Shopify store, a combination of what @Harsita has outlined and the change I mentioned to your theme.liquid file is how you do it. I’ve tried a million different things before that did not work. This is it.
One thing I will say is that it oddly didn’t push the change to my site on mobile but instead changed to a similar font. No clue how this happened.