Every order that deals with custody and visitation must also deal with child support. The order must have a child support calculation attached. Parents cannot "waive" child support.
Child support is a mathematical calculation. Some of the biggest factors that impact child support are each parent's gross monthly income and the number of overnights each parent has through the year. Sometimes the child support calculation will require the child support obligor to pay $0 per month, but this is not a waiver of child support.
Sometimes parents can agree to deviate upwards or downwards. Deviations are limited to specific circumstances and subject to approval by the judge.