Except the First Amendment has been incorporated to the states. A state can’t establish religion, restrict free speech, etc.
But they sure have power when it comes to the 2nd Amendment.
I would say it has erroneously been broadened into limiting individuals who happen to work for the public or use public facilities. The First Amendment is a specific limit upon the Federal Government, not the people. The specific limit entails a limit upon Congress, not the Executive or Judiciary -specifically, Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof;
Who incorporated it? The US Supreme Court--on its own, and with no Constitutional authority to do so. Others have answered this. I just wanted to add that the idea of "incorporation" is just the name put on a unilateral creep in authority claimed by Left-wing ideologues on the US Supreme Court during the 20th century. There's no foundation for it. The USSC has seized authority over individual Americans from the States.
The USC is designed so that if you don't like a State's laws, you can move to another. This is designed to keep the States honest and free.
What Leftists have claimed that the USSC's power-grab is based (somehow) on the 14th Amendment--which is explicitly about slavery and nothing else. The Court's claim that a State can't endorse a religious denomination is nonsense. It's Congress that can't do that.
The function of the Amendments is to emphasize certain limits--which already exist in the structure of the main document--on what Congress is allowed to do under the USC. The fact that the 20th-century Supreme Court turned this idea on its head just means we need to turn the Court on its head. This is the core issue in taking back our country. One thing I have liked about Ted Cruz is that he gets this. It may start with impeaching justices wholesale from the entire Federal bench. Whatever it takes!