Give up on the basic concept of reading music for now. Seriously until you become comfortable with the guitar; you should not worry about reading sheet music. It requires a lot more work than it's worth for a beginner, later on pick it up again. Learn to read tabs and chord charts.

Tips for holding a guitar: Have the guitar resting slightly on you(if sitting). Hold the next up slighty and keep your thumb behind the neck. Arch your hand and try not to keep your fingers close to the fretboard as humanly possible.

It just takes a lot of time to get use to the chords and changing chords, but I promise if you work at it, it'll be like second nature.