Even though people under the age of 18 cannot hold shares directly, you can start investing on behalf of them from day one and when it comes to investing, time is your best friend.
Time allows for the magic of compounding to take affect and we always advocate for getting started sooner rather than later. Saying that, the number one rule of compounding is to not interrupt it unnecessarily. This means you should ensure you have your day-to-day expenses and an emergency fund for those unexpected expenses. This will give you a comfortable cushion and mean you can sit back and let the investment compound for years and decades to come.