just wondering if this is possible?
I find out that the regular font was free. So I tought maybe I could use it on a wordpress theme I am designing. I will sell it on themeforest.
In general: no. Think of it as a standard commercial font which just happens to have a price of $0,00.
It has a typical license agreement (EULA) of a commercial font, which would not allow distribution/resale.
But you can simply ask the designer if he is willing to allow the use you are interested in.