The National Center for Education Statistics (NCES) is one of the main resources for educational data. This information is highly trustworthy and authoritative in nature. The NCES describes itself as the "primary federal entity for collecting and analyzing data related to education in the U.S. and other nations. NCES is located within the U.S. Department of Education and the Institute of Education Sciences. NCES fulfills a Congressional mandate to collect, collate, analyze, and report complete statistics on the condition of American education; conduct and publish reports; and review and report on education activities internationally" (https://nces.ed.gov/about/).
The NCES website has many different data sets which may be able to answer your educational data questions. The following are some of the commonly used and important data sets collected by the NCES.