Are u serious , for one if you are posting in the starting with gamestudio, i would assume you have no experience with the engine or game design, and also to make a game like oblivion would take a proffesional (on his own) about 5-6 years , unless they work on it 24/7. If i was you i would start with a small project , maybe find the RPG template and make your own small RPG , do this to get experience.