Many of these are national companies or franchises and may or may not provide true representation and job opportunities. Their goal is not to charge you money for their services but rather benefit economically from paying jobs that they set you up with . Define what the purpose is in getting involved in modeling. If it's any of the latter reasons, then local opportunities are your best first step. If a career is really what you're seeking, then you'll want to meet with a reputable agency.
Local opportunities can run the gamut.
Although most local opportunities are free or non-professional, they do allow your child to gain not only experience but also the poise and confidence that will make them successful throughout their lives. Photographers - Let your photographer know you'd be happy to have your child's photos displayed. Kid's events are always good for drawing traffic. Word of Mouth - Get the word out amongst others with the same interest. News of opportunities travel fast in small circles.