Even if you do manage to find a solid Game engine. Your still going to have a TON of work on your hands. It's Takes big studios, like Epic, and ID, months, and months, to create a Game, even if they use a preexisting game engine. AND thats with large numbered groups of Highly experienced, and talented Individuals.
Being a noob, as you are. This would be a NIGHTMARE!!! You would have to take on the rolls of: Designer, Character Modeler, Animator, Prop Modeler, Level Modeling/editing, Programmer, Lighter, Rigger, texture artist, ect, ect, ect...
I would recommend joining a MOD project, there are plenty of them online. All looking for people to create Game assets, for them. This would be a great opportunity for you to get your feet wet, and to see just how much work goes into just simply Moding a Game.
Then you can start to look into creating your own game, once you have an idea what sort of a challenge your in for.
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
[long pause] "Friend!!"