Did the universe pop out of nothing?
Assuming you mean literally nothing, then no.
The idea isn't even logically self-consistent. There can't possibly have been a time at which nothing existed for anything to have popped out of it because time (space-time) is a something.
This is simplistic Newtonian thinking anyway. The best theory we have of the universe as a whole is general relativity and that gives us the picture of a "block universe". The whole space-time manifold just exists and time is a (observer-dependent) direction through it and hence entirely internal to it. The manifold just exists. Looking at the past time-like direction through it to find out why it exists doesn't make any sense.
There are other hypotheses (of quantum gravity) but the very existence of this one picture illustrates perfectly how daft trying to argue for a god from a "first cause" or "cosmological" type arguments is.
Even if we were to ignore that (and all the other fallacies they are riddled with), we clearly don't understand everything about the physical world and that is all these arguments could possible tell us.
We may never know why the universe exists but its existence is no less unexplained and mysterious that the existence of some sort of god that we might posit to "explain" it. It just replaces one mystery with a bigger one.