I am also a beginner with large fingers working on the same string issue. I have found what everyone is saying here is quite true. Slow practice is the real key, but adapting lessons to your own individual hand restrictions is a big help. I have also found lifting the guitar head much higher (even to the slightly above your own head) helps a lot because it decreases the angle of your finger tips to the fretboard thereby allowing them to come down more perpendicular instead of sideways. That will allow you to land in the space between strings. It will also help you maintain the string pressure without hitting an adjacent string as your fingers tire and roll around. Then as you improve, you can slowly bring the guitar head down until you find your comfort level (or leave it high like many Spanish guitarists). Your fingers will fit, it just takes lots of practice. Just remember to go slowly at first to build up your finger memory and have fun! That, after all, is why we do this in the first place!!