you should just go DO IT !!
worst case...youll have tons of fun.
just an idea....instead of starting on acoustic (some might disagree)....
i find that some give up learning useing acoustic guitars cos its tougher on the hands initially.......so sometimes i suggest starting on electric.
the music stores are choc full of dvd's on learning guitar ....rather than learning something like twinkle little star ...which gets boring.
if your REALLY serious also check out a product called "the guitar master class series and video guitar lessons.." at pgmusic.com.
here are the links....
http://www.pgmusic.com/products_vgl.htm http://www.pgmusic.com/products_mc.htm
by folks like miles black, and danny casavant etc.
these are really neat guitar training products.
happiness.