Many people have the misconception that it is better to start lessons on an acoustic guitar and then "graduate" to an electric guitar. Or, they assume that playing an acoustic is vastly different from playing an electric. It's not, although there are different techniques involved.
The difference between acoustics and electrics is like the difference between pencils and pens. In a pinch, either will do, but there are distinct advantages to one or the other in certain situations.
For example, you'll do crosswords and calculations in pencil, but sign your name with a pen. Likewise, you'd play "Blackbird" on an acoustic, but "Back in Black" on an electric, although it is physically possible to play each song on any guitar.
Also, when it comes both to musical instruments and writing implements, there are variations in technique that are minor for the beginner, but significant for the expert. A professional illustrator will be a master of certain shading techniques that can only be accomplished with pencil; hand-addressed invitations require specialized skill with a calligraphy pen. An acoustic guitar can be strummed vigorously and percussively in a way that the electric can't. Meanwhile, electric guitar makes use of string bending and lots of sustain (think "Wonderful Tonight" by Eric Clapton) that is virtually impossible to achieve on the acoustic.
As a beginner, a student can explore the guitar starting with whatever instrument is lying around. The fact that there are so many different kinds of guitars (and sounds that can be made on them) is part of the mystique of the instrument.