Does everything have a cause?

Yes. Look at the structure of reality and every single thing has a cause, including the creation of the universe, because the structure is a causal loop. A cause here is a read. One record depends on another when it certifies that it read a value the other wrote, and the chains of such reads are the entire causal structure there is. Inside the world those chains run from earlier to later, and many pairs of events have no chain between them, which is why they have no fact about which came first. The universe as a whole is caused too, by itself. Its observers reverse engineer it and build the screen it runs on, and the screen computes the universe that produces them. The loop needs no earlier moment to start from, because time itself is the order of reads inside it. The creation of the universe is caused by what it creates.

Also in Chapter 9: What Move Does Reality Actually Make?, Chapter 2: Why Is There Anything Rather Than Nothing?.