The discussion is here, and now...not some distant future.
First cause cannot be verified, making any discussion specious....but, for argument's sake.....
First cause is never temporal, for it explains the reason for everything, therefore beyond defining.
Time is measurable within the context of what is known to human life.
The universe had a beginning therefore there is a causation that created the effect we call the universe.
A cause is the sine qua non for an effect: if no cause, no effect.
Leading us back to the question of the first cause. A question that remains unanswerable unless one is prepared to consider that all that exists is, because the first cause made, and is making everything that exists. For we know that the universe is in constant expansion, therefore we can conclude that creation continues. We can further argue that the first cause remains the causation of the continuation of all that exists.
Reason invites each of us to understand that knowing, all that we know includes knowing, that we know so very little.