I started with Maya 4 many moons ago. It doesn't have all the bells and whistles of the current versions but does have the basic tools for poly modeling, lighting, rendering, writing expressions, animating, etc. If possible, see if you can pickup a cheap used copy of Maya 4 Fundamentals from new riders. That's what I started with and it will get you up and running pretty quickly.
The biggest downside to having an old version is not being able to follow certain tutorials that use newer features or being able to open newer sample scenes but at least you'll be able to produce without the watermark of PLE.
I disagree with most on here that you need the latest and greatest for learning how to model. You can download Maya PLE like "who" suggested if you want this. Otherwise, use 4 and hone your sculpting skills and look for some older scripts to help on highend3d. Folks forget that Maya 4 was used in quite a few pipelines for major pictures back then.
"Terminat Bora Diem, Terminal Auctor opus."