The kind of instrument you choose reflects the type of music you respond to at the time of purchase. I play classical guitar now but I originally learnt to play electric guitar, having mostly listened to it through rock and pop songs. When I first went to Dublin as an engineering student, I went to hear a classical guitar concert by John Williams. It completely knocked me out that the guitar could be played to such a high level and I decided I wanted to learn to play like that.
The technique is quite different on classical guitar - it is very demanding technically, especially at the beginning. There is a certain level of technical "head-room" required before you can express yourself through the music or create any sense of your own style. This can discourage people initially but once some level of technique is achieved it becomes a pleasurable experience.
Classical guitar teachers weren't exactly two-a-penny in Ireland so I had to teach myself to read music and play. The first classical piece I taught myself was the well-known Spanish Romance (composer unknown). Then I became more ambitious and learnt Leyenda by Isaac Albeniz, a popular classical piece that caught the imagination of many electric players, including myself.
The main appeal of the classical repertoire is that it embodies a great variety of musical styles - ranging from 16th century works to music written by contemporary composers. There are many wonderful classical players these days - John Williams, Julian Bream and David Russell, to name but a few.
With classical guitar the playing position is different; we generally sit down and use a footstool to raise the left foot, which positions the neck of the guitar higher than you generally find in other styles. This frees the left hand from holding the instrument so that it can easily and freely move up and down the fingerboard. In addition, we use the thumb and first three fingers of the right hand independently - it is almost like using four different picks at the same time.
Another difference between the classical and electric guitar is that the wood of the classical instrument is fundamental to the generation of sound and colour. Also, the nylon strings create a very different sound than the steel ones used on the electric or acoustic steel-string instruments. Although it varies from maker to maker, the distance between the strings on the classical instrument is usually wider to create higher tension.
When you play any style of music you have to be excited by what you are doing, and this is also true in classical. Initially, particularly as I was self taught, I found it very helpful hearing each piece played in it's entirety on a recording, to get used to the sound and style. The most important thing with learning to play the guitar is that you enjoy it, the enjoyment factor motivates you and makes you determined to keep at it.