Hi Doode,

I am a bit blur here which one do you to change the font style and size.
In able to change the style and size of font, you can make template override, which change it on custom.css in your current template.
DIR: /templates/<YOUR_CURRENT_TEMPLATE>/css/custom.css

You can refer this documentation on how template override works:
EasyBlog Template override
Easysocial Template override
EasyDiscuss Template override

Please give it a try . Please bear in mind, the customization is on your risk, as already stated on ourSupport policy