Try with a children's size guitar at first (there are some cheap Spongebob Squarepants guitars which look really cool and are highly rated, or an Ibanez mikro, which I would recommend also, especially since I only use Ibanez guitars!), as they have smaller frets, and then after that feels comfortable, then move onto a bigger guitar. Accoustic guitars are also good for this, when I started at 13, it was with a full size accoustic, and my tiny teenage hands had to stretch and adapt, plus it builds up dexterity when it comes to electric, which use thinner strings and low friction necks. Also try some
finger stretches which are amazing after a while, I couldn't fret chords until after doing them.
The standard budget guitar is a Fender Squire, and you can get a second hand one for under $100 (try local pawn shops or ebay), tough they're really weak flimsy sound, but ideal when starting out. They're quite tough as well and can take a beating. I set mine on fire (because I'm so fucking hardcore) and have since rewired it back together, and it allows me some neat music, as all character/tone has gone from it, so when I play through effects, only the effects come out so it sounds kinda synth-y.