Who says they succeeded the very first time?
The same or similar processes were probably going on at numerous different volcanic vents ("Black Smokers") or on clathrates or in some other micro-environments during the vast Archæan Eon for hundreds of millions of years before one managed to achieve sustainability. Countless populations undoubtedly arose and perished before the "right" metabolic path was finally found.
(And always with the "Straw-Manning!")
Suppose there are creatures that can reproduce copies of themselves. How did these creatures make the leap such that reproduction requires a sexual mating? And the creatures can’t go back to not needing a mate for reproduction? And why are there no creatures that require 3 (or more) different individuals to produce one new creature with the variations that would occur from requiring the multiple individuals?
Oh, this one is easy-peasy!
The assumptions implicit in your questions - actually, some of them are explicit - are simply WRONG! As in: You're mistaken!
There are species that have more than two sexes, for instance. And some vertebrate species that once had two sexes have reverted to parthenogenesis ("Virgin Birth") - the males have simply ceased to exist! Etc.
I note that it is easy to "poke holes" and/or pose seemingly clever questions about a field of knowledge about which one knows so very little!
The Dunning-Kruger Effect is in full play here, folks!
Regards,
Well then educate me. Name names.