The first part just means that Congress cannot regulate established state churches (https://live-bri-dos.pantheonsite.io/activities/handout-c-ma...), while the second states that Congress cannot prohibit people from practicing their religion.

What the first amendment doesn’t do is exclude moral beliefs rooted in religion from being the basis of public policy. If the government can regulate conduct that kills living things, then it’s immaterial whether any particular legislation is rooted in the moral framework of Christianity or Islam or Feminism. In the American system, all moral frameworks, whether rooted in religion or not, are on equal footing. That’s distinct from secularism, as practiced by France and formerly Turkey, where religious philosophy is singled out and excluded from the public sphere.