Kid!!
First, if you wanna earn good in this world then dont aim for gaming as the only industry....its not the most rewarding industry for developers n designers..rather choose a primary industry like for designing go to media companies, and work there, while keeping game designing as your second choice.
Second, there are many disciplines in gaming: coder, level designer/director, 2d/3d artist, 3d animator, project manager/teamlead, QA testing (code,gaming,etc)
Choose which discipline to use, and stick to it.
Third, use existing gaming mods to increase knowledge on how game engines work. Make your own mods, or use existing games level designers or use gaming kits like Unity or UDK.
For more info go to moddb.com