The complainant is probably going to tell you they have searched everywhere. You need to acknowledge their efforts and then conduct your own search. I have cleared many a missing juvenile by finding them hiding in the same area the parents said they searched.
If you don't find the child in the area of the point last seen, you need to expand your search in a number of ways. You can conduct a crime scene search where the child was last seen, go door-to-door, or structure a grid search. In some cases, a roadblock search is warranted. Because people are creatures of habit and tend to take the same route each day, roadblock searches sometimes produce witnesses who saw the child, observed someone hanging around the area, or who remember an out-of-place vehicle.
As more units arrive, organization is critical. You need to assign specific areas for officers to search. They need to document every address and person they speak with. Assign a few roving patrols to go check specific roads, trails, parks, or other points of interest based on your interviews. If your initial search doesn't find the child, you may have to reach out for other resources.
At some point you may have to consider bringing in K-9 and aviation units. You may need additional volunteers. Don't discount the Civil Air Patrol, which has a built-in search and rescue function; civilian search and rescue organizations; and even police academy cadets. Think outside of the box when it comes to finding ways to expand your resources.
Winding Down