Sorry to dampen your spirits, but it really isn't as simple to develop a computer game as you think.

Can you create mathematical equations to describe the actions of people in the game?

Can you create 3D models and program how they should move?

Etc, etc ...

Again, sorry to dampen your spirit; but don't let it put you off! you will probably be able to eventually do all those things if you tried hard enough for long enough.