The universe as we know it may have begun to exist. Or it may not.
If a god is put up as the first uncaused cause, one could put up anything which is sufficient as an uncaused cause. There may be some perfectly natural uncaused cause we just don’t know about. The universe as we know it may have budded off from some pre-existing universe ~ maybe, maybe not.
To propose “God”, as that uncaused cause is special pleading, (Wikipedia on ‘Special Pleading’). Can that uncaused cause, (a god), be proved, any more than any other notion of how our universe came to be here? (Spoiler: { Answer = “NO” } ).
Cheers, Mutorc S’yriah.