Example requested for font changes in skeletons

I am using the X Corporation skeleton, which is great except fonts and fontawesome icons are too small and have poor contrasts. The learn dot getgrav page section 16 explains ways to make font changes in markdown language, however, none of the examples seem to work in the skeleton. I also found a recommendation to write a CSS or other code to change fonts but 1) I don’t have the knowledge to do that, and 2) I don’t want to put the time into learning it if it’s not going to work anyway. Maybe this is solved if the Admin plugin will work. But it does not - it’s generating errors and is the subject of a separate posting. Suggestions appreciated… thanks!