What size acoustic guitar should I get if I am a beginner, yet I aspire to hone my skills to a more advanced level in the future? Is there a particular dimension that would best accommodate my relatively small stature as a child, or perhaps a full-sized instrument that might seem daunting yet offers room for growth? Should I consider the varying types of acoustic guitars available, such as the parlor, concert, or dreadnought, and how each of these shapes might influence my playing comfort and sound quality? Would the decision be largely based on my age, physical size, or even my personal musical aspirations? Can choosing the right size truly enhance my learning experience, or is it merely a trivial detail in the grand scheme of my musical journey? How critical is it to test different sizes before making a purchase, and could the wrong choice lead to frustration or discourage me from pursuing my passion for music?