Hello Jyll,
Thank you for submitting a question on changing fonts on home page. What do you see instead of the Customizer menu that the tutorial shows? Is it a blank screen? Is it a Customizer window without the Font option? If the Customizer is not displaying the options that should be there then there is a deeper systemic issue. For example, BoldGrid may have been installed incorrectly. Otherwise, we may just need to get a better idea of what you see so we can help you find the Font options.
Best,
Christopher M.