For Windows:
1. Start PDFelement， Click Back > File > Preferences > Font , set the Options
2. And then you can change the default font type as you want.
For Mac:
In the Mac version, the default font of the text cannot be changed directly, but PDFelement will remember the font setting last time.
For example: when you set the font type to A font, and then add text, the next time you add text, the A font will be used by default.