As nice as it is to have free software, chances are you will eventually have to shell out and buy something pro quality, (your engine, your 3d app, your 2d app, etc.).
There is no easy way out, short of buying your assets when it comes to game or animation creation.
If you are really serious about building a game that you can sell (important), that people will buy (more important), you will soon have to realize there is no way that's gonna happen without some serious work and a little bit, (or a hell of a lot) of cash expenditure.
You're not going to do it for free.
You're not going to do it over night.
You're not going to do it without a substantial amount of learning at some or every level of the process.
If you know nothing about any of the processes, research, research, research......
Try modding a game first, or get involved with a mod team once you've gained some skills in one of the processes (modelling, animation, effects creation, coding, texturing, etc.).
Becoming half way decent at any one of those skills takes at least a year (or more if you are self educating) of diligent and time consuming activity in that field.
Ask anyone on here how long it took to get to where they are in their project (Ron, for instance who now has his website and game up and running)....it's not an easy process, but can be very rewarding.
Enthusiasm is great, but it doesn't replace skill.
The hardest part for most beginners is the realisation that the software rarely if ever does the work for you.
It would be like buying a pack of crayons and expecting to create the Mona Lisa just by taking the wrapper off and opening the box....there is no crayon that's marked Mona Lisa.....
Reminds me of when I first started learning guitar. I thought if I slept with it, I would magically become a shredder....5 years later, it happened! (had nothing to do with practicing till my fingers bled.....).
That being said, here are a handful of links for totally free software and some tutorials on how to use them:
3d content creation:
http://www.blender.org/download/get-blender/http://www.blender.org/education-help/tutorials/http://www.turbosquid.com/gmaxhttp://simviation.com/gryphon/tutorials/gMax_00.htm2d content creation:
http://www.gimp.org/http://www.gimp.org/tutorials/It's a start, but they all have a learning curve, some a lot steeper than others, and not one is gonna give you Crysis after a half an hour of work....but if it was easy, everybody would be doing it wouldn't they?