Start with the “out of Africa” scenario (which seems most plausible). As groups resembling the “missing link” continue moving north, eventually, an evolved mated pair breaks off to form a new group somewhere near the intersection of the Tigris and the Euphrates…
The other thing to consider is this: do you believe that Christ died and rose again? Do you believe in the miracles Christ performed? What about the miracles of the Old Testament?
If you believe those, why must the events surrounding creation be “ordinary”? Isn’t it possible for God to have taken a pair of hominids and performed a miracle - making them Adam and Eve?
Some things are really matters of faith, but that doesn’t mean that we can’t examine them with a scientific mind. Sometimes, however, we have to be prepared to accept a miracle (e.g., St. Juan Diego’s tunic).