It's not gonna happen unless you wanna drop $10k+ on a super computer. You'll lose money trying.
What kind of task I have to complete on this site? How much I can make from this site?You could try sites like these and earn bitcoin for doing small tasks, way easier than mining http://bitcoinreward.net/ is highest paying one I know the rest are faucets, you can search google for "bitcoin faucet" but you have to put in alot of time to collect from each one for such a small reward.