"No Child Left Behind" was replaced a decade ago with the "Every Student Succeeds Act", which also reauthorized the Elementary and Secondary Education Act, but actually narrowed the Federal government's role in elementary and secondary education.
Without getting too far into the weeds, ESSA/ESEA don't directly establish schools, develop curricula, set requirements for enrollment/graduation, determine state education standards, or develop/implement testing to measure whether states are meeting their education standards.
Instead, what it does do is provide additional funding and grants for things like disability/low-income accessibility, de-segregation, school improvement efforts, career counselors, etc. It authorizes some assessments to make sure schools are eligible for the grant programs, but leaves the States a lot of control on how to make those assessments. Basically: some optional extra money with strings attached. End the only enforcement mechanism is withholding the funding...
And while it varies wildly from state to state, and district to district... it's not particularly a lot. K-12 school federal funding tends to hover around 10% (a bit more lately, with COVID provisions), as opposed to state and local funding.