Font Change in da vinci theme.


Hi all,
I am new to this forum.
I was introduced to the dropshipping concept before a week. Since then I read a lot about it and decided to give it a try.
Today, i purchased the plugin and installed da vinci theme on one of my newly bought domain.

I want to make some changes to the font, font weight, and size. When i ask for support, they are asking me to signup for a different service. However, i want to do it by myself. Can someone help me with some example codes for making customization with the font please?

It would be highly appreciated.

May thanks