Fonts don’t cause the loading too much rather than the other content of the website.
In your case you are only using the fonts that come with the theme and there are no unnecessary files that you can disable or remove.
In general, our theme is already optimized and doesn’t have too many resources to make your website slow. Most likely, your website performance suffers from the content you have added to your website.
It may happen in case of too many plugins, large not optimized images or other resources. So we suggest you remove unnecessary plugins, install some kind of JS & CSS optimizing plugins like Better WordPress Minify and a caching plugin like WP Super Cache. Also, you can use GTmetrix tool to see what makes your website slow and optimize these parts of your website.