Of course, you are right. This ammendment clearly only prevents Congress from outlawing a religion or specifically establishing a state religion. It does not mean separation of church and state. The term "separation of church and state" is not in the Consitution. And of course, it only applies to Congress, not the states.
It should be obvious then that school prayer is not unconstituional because it does not involve an act of Conbgress establiushing a state religion or prohibiting a religion.
But the Elite that controls the USA has an agenda that involves destroying Christianity. So this Elite purposely perverts the real meaning of the Consitution to make it look like the Consitution supports their anti-Christian crusade.