I'm 100% certain that the IRS is very concerned with any amount of money any of us make regardless of age. I don't get the it doesn't matter cause your young approach. By age 16 I was paying taxes, contributing to social security, and filing 1040's.
Alex, look you and the thousand other new guys that come on here every spring rely too much on bad internet advice. The state of NJ has countless pages of accurate advice on starting a business, as does small business association and a few others. Take it for what you want. If you want to putz around and not make any money than go ahead just do not rear end me cause I'll sue your family for all they have. On the other hand if you want to start a business that can support you for the rest of your life, raise your children, put them through college, and allow you to retire happy than take the time to do this right.
This site will verify much of what you have been advised and get you pointed in the right direction.