If you are new to guitars, you can learn to play on just about any guitar, but learning to play on an acoustic guitar is probably recommended since it is easier to migrate from an acoustic guitar to an electric guitar than the other way around. This is because the mistakes that you make on an acoustic guitar will be more noticeable and not be hidden by the electronics of an electric guitar.
The strings on an acoustic guitar are also a little harder to properly fret so you can be sure that if you can play a chord on an acoustic guitar then you will also be able to play it on an electric guitar. The necks and string spacing are also generally a little bigger on acoustic guitars so your hand positioning and fingering technique will develop more quickly by the exercised dexterity that you will gain on an acoustic guitar.
Used acoustic gutars are a great way to start with and learn on because you will get a better quality guitar for your money. A used acoustic guitar will also be properly broken in and set up if you take care in your purchase and buy from an experienced guitar player that has properly cared for their acoustic guitar. Instead of paying a couple of hundred dollars for a new guitar that will be made of lower quality woods and components, the same amount of money will allow you to obtain a quality used acoustic guitar that will sound better and play better than a lower quality acoustic guitar.
Most serious acoustic guitar players will tell you that Martin and Taylor are the best acoustic guitars, followed closely by recommendations for Guild and Gibson acoustic guitars. Most of these companies offer low to mid-level guitars in their lineups that can be purchased new for $500-$1,000, but you can often find these same models selling for up to half of the cost of new guitars by buying used acoustic guitars.
You will find Martin, Taylor, Guild and Gibson acoustic guitars being used by professionals at most music festivals and concert arenas. They are being played because of the quality construction and the great tone that they possess. Spend your money on a lower entry model from these manufacturers and buy a used acoustic guitar, and you will have the satisfaction of knowing that you have a quality guitar to learn with that will lead to a more enjoyable and worthwhile experience.
Although there are other quality acoustic guitar brands out there than the brands that I mention, their boutique nature and lack of availalbility will generally result in a higher price in terms of both new and used acoustic guitars in these lines. Stick to a quality brand that is in ample supply in the secondary market and you will be able to play what the pros play at a fraction of the cost.