The first step to learning an acoustic guitar lesson is to pick up an acoustic guitar and learn to tune it. This is not as difficult as it sounds. There are many tunes that only need a single note to play, and some just need a chord. The way to tune an acoustic guitar is to look at it and figure out its string numbering. (This information should be found on the instruction manual.)
A twelve string acoustic guitar is typically a steel-tipped steel guitar with 12 necks, making a much louder, thicker tone than a regular six-string. Typically, the 6th string is tuned to unison, while the other strings are tuned separately in octaves. They are much easier to play than their six-string counterparts. Most people who pick up an acoustic do so with a left handed version.
If you are looking for a left handed 12 string acoustic guitars, there are several options available to you. You can go to a music store or search online for used ones, or you can purchase one online. For a lot less money than you would pay for a new one, you might be able to find a used model. Also, many stores will sell used models from other guitar brands. It's important to check out the company itself. Be sure to check their credentials.
Many left handed 12-string acoustic guitars are also fitted with a bridge, or middle person, on each string. This makes them "smooth" in sound, and prevents them from hitting your head when plucking. Many older models have this type of bridge. It is very common on the J and B strings. There are some newer versions without the bridge that do not have this effect. But for many people, it's worth the extra cost.
The price range of a guitar will depend on the amount of frets and the number of strings. Some acoustic guitars can only handle six strings, and others can handle twelve strings. If you are only going to play one or two types of songs, you can get away with a six string guitar. On the other hand, if you like to play a wide variety of genres, you may want to go with a twelve string. There are many models of electric guitars that have the ability to handle six, eight, ten, and even twelve strings. So make sure to ask your dealer which models he prefers.
Another feature to consider when buying an acoustic guitar is the type of bridge that is installed on the neck. Most guitarists choose between a G-brace or a T-bridge. The G-brace bridges the sixth string up to about E-back. They are typically cheaper, but tend to have a less solid connection than the T-bridge.
Another advantage to the 12 string acoustic guitar is that the individual strings can sound independently of each other. You don't need to play all of the strings at the same time. You can let one or two low notes ring out, and then focus on the high notes. This is not true with a six string guitar, where all of the strings must be played at the same time. There is only one open string, so you'll want to make sure to try out a few different types of notes and sounds to find out which sounds best.
Don't worry too much about choosing the right sound for your acoustic guitar. Most amateurs are able to play most songs well on a three or four string acoustic guitar. If you're playing rock, folk, or blues music, however, you'll need to check out whether you can play those songs with only three or four strings. Your ears will be able to tell you if you're hearing notes that other acoustic guitar players are playing during your practice time.