If you did, you would know the answer: there is NO First Cause.
There is no static —> dynamic Unmoved Mover. Rather, it is a beginningless chain of dynamic causes (dynamic —> dynamic).
In one fell swoop, the Gordian Knot that has bedeviled theistic philosophers is cut, and atheism’s only positive argument is shattered. Theists can finally go on the offensive against atheism since the traditional explanation that was derived from Aristotle has proven woefully inadequate since it contains two fatal logical flaws.
We crossed paths in our post. As I understand your answer there was no creator (for sure in Mormon theology), existence always is and has been, and existence itself created God rather than the other way around. Atheism rather than agnosticism.