Look for the block which is partially break, it has ore inside (the deeper the ore the more valuable the ore is). Then you return the ore to the shop is sell it. You will then see how much you earned on top right. Once you accumulate 100μ (which should take about 30 minute - 1 hour) you can have your first withdrawal.

Note: You have to create an account, if you play without creating an account then you are playing demo.