Victims of Child Abuse Act Reauthorization Act of 2018 (Sec. 2) This bill reauthorizes for FY2019-FY2023 grants for local and regional children's advocacy centers (CACs), as well as for technical assistance and training. CACs coordinate a multidisciplinary response to child abuse. The bill adds a new finding specifying the need for state chapters of CAC networks (1) to help local communities coordinate their multidisciplinary services, and (2) to provide oversight of, and training and technical assistance in, the effective delivery of evidence-informed programming. It modifies grants for regional CACs, including to add, as a new program objective, collaboration with state chapters; and to require regional CACs to assist local CACs, multidisciplinary teams, and state chapters, in addition to communities. It also modifies grants for local CACs, including to add, as a new grant purpose, promoting the effective delivery of the evidence-informed Children's Advocacy Model and the multidisciplinary response to child abuse; to allow grants to support direct services for victims of human trafficking, in addition to victims of child pornography; and to require a portion of grants to be distributed to state chapters. The Department of Justice must report annually on efforts to monitor and evaluate the program activities of regional CACs and the extent to which both urban and rural populations are served by the regional CAC program. (Sec. 3) The bill provides immunity from civil and criminal liability under federal, state, and local law for people who make good-faith reports of child abuse or neglect or who provide related information or assistance.