I received a ton of help from a previous question and used:
html * {font-family: Helvetica !important;}
But for some reason it still doesn't change in the product descriptions. Everywhere else it is working fine. I see !important used a lot and I fear this may be the problem but the css file is massive and not designed by myself. I'm not sure what to do now.
It sounds like you will need to just be more specific than the template css.
If the template css uses
You would need to use something like this to override it
You could also use inline styles to get a higher specificity than styles inside a stylesheet.