Interesting question. It ultimately depends on the individual state you're trying to form in.
Like Delaware, New York has no age restriction for forming an LLC. This is in contrast with New York’s requirement for corporation directors to be at least 18 years old. Nevada has no age restriction either, which is important because this is often considered, with Delaware, to be the top state to set up an LLC for individuals in less-management friendly states.
The fact that you have the ability to form an LLC in Nevada or Delaware as a minor provides you with a few great options. However, even if you are able to form an LLC as a minor, your ability to freely contract with others may be limited because of your age. Therefore, your inquiry digs deeper than simply researching an age requirement for formation and it’s important to seek legal advice before you establish your LLC to see what your options are.