People have a tendency to mess around with default settings before having any users. It wastes time and usually means slower, less secure sites.
If you’re using WordPress, use the default theme. Upload your logo and the content for your about, contact, product, etc pages. You might surprised how good it looks. Just launch. If your product is good enough, it will sell. If it doesn’t sell, it probably isn’t because of your fonts. Solve your biggest problems and then worry about the shade of your business card.