first thing to do is writing a game design docunment.
than do a taskplan and an asset list.
than try to remove as much as you can from your document to shrink the project th the basics!

think of it, you can always add things when importent things work like the shall.

than^^ ... go through the Online tutorials:
http://tutorial.3dgamestudio.net/

and look at the aums...

that will give you a good start^^