Some time ago a young student arrived at my studio for her first lesson with a new guitar an uncle had bought her as a surprise birthday present. It was an inexpensive model and there was nothing wrong with it as a starter instrument…except that in proportion to her size it was like an adult trying to hold and play a double bass as if it was a guitar.
Diplomatically, I pointed out that she needed to grow a little before it would be the perfect size for her. The parent and the child were a little put out, but I keep a three quarter sized guitar in my studio and when I let her try it, they both agreed it was much closer to her requirements.
The parent was happy to go away armed with a couple of recommended guitar shops (sadly I’m not on commission). I gave some additional advice about what to look for and cautioned the parent, not to pay too much for a first instrument. They reappeared a week later with something more satisfactory.
When you buy a guitar I still think it is best to see it, handle it and get the feel of the instrument before you part with any hard earned cash. I know many people (including myself after careful research)who have bought instruments on-line with good results, but photographs and reviews can only convey a limited amount of information. That said, I do think the quality of guitars has become more consistent in recent years, and you get better value for your money at the “starter” end of the market than I would have expected in my younger days.
If you are buying for a child, the guitar needs to be the appropriate size, so the youngster can hold it correctly, and use the fretboard without strain on their growing hands. There is enough to ponder and assimilate when you start playing a musical instrument, and the last thing you need is to turn the process into a balancing act.
Guitars commonly come in half size, three quarter size, and full size. You can also get them as seven eighth instruments, there may be other sizes as instrument manufacturing is evolving all the time.
Other than that the range of instruments is vast. It depends upon the type of music and sound you want to produce.
Set yourself a realistic budget, don’t pay too much if it’s your first instrument, and go somewhere that has no problem letting you try out a range of guitars. A good dealer won’t hurry you, try to blind you with too much technical detail, or foist something upon you beyond your budget or experience.