In Wordpress, fonts are controlled by the Cascade Style Sheets (CSS). There are style sheets for each of the themes.
I suggest that you create a child of your theme before you attempt to play with changing the CSS files.
You will find the CSS files under the menu for “Appearance” and “Editor” or “Edit CSS” with some plugins installed.
The fonts or themes have nothing to do with DreamHost. They are all equally good and all equally bad.