If you can do it using styles without any complications depends on the design and purposes ot the sheet(s).
If there is a set of cells (ranges) that will always present numbers (content or formula results), and another set always presenting text, you can doi it basically with two cell styles for which the respective font attributes are set differently.
If your sheet is a huge range of cells not specialized for one of the two cases, you can do it again wth two (or a few) cell styles, and one CondiotionalFormat
setting.
If you need CF for different purposes, you need …
You see, I wouldn’t expect a reasonable answer as long as you not give more details.
A specific “conditional font” setting does not exist.