I don't really thing that your character doesn't know how to mine, I think that you don't have a pickaxe with which you can mine. The pickaxe can be bought from the forge and also (just in case) you can mine in the tavern's basement.
Aiodos I already have the pickaxe but nothing happend, it's just the same text "you don't know how to do the work until you learn It, maybe someone in town should know something" and nothing happend, I don't know what to do
Then, maybe it's about stats: perception for find resources and endurance so your character can work out longer, bc you can't mine forever (same goes for chopping wood). If that isn't the case, I don't know other explanation.
Aiodos I already figure it out, have to find the Diabosite in another place then show it to Blake, then you can start minning and continue with the Full Moon quest, a little desperate but finally can move on
