Basically one universe had to be the first and then all the other parallel universes or alternate universes had to come about through supposed different decisions etc. that the original or Prime universe made. We all call the TOS the prime universe but how do we know that ? Was it the first or real universe than all the others that followed were created after. I wont bore anyone with the physics but supposedly there are alternate or parallel universe out there that are basically slightly different then ours and may have happened differently. We all have a myriad of decisions we make each day but may have wanted or nearly made a different decision which is where parallel universes may get their start. So in Star Trek the question is at the beginning of the universe there was supposedly just one then the parallels came later. Do there has to be a prime or original universe. Is it TOS or another?
The first Universe is the one we see in
the Cage. Vulcans there smile. The Enterprise is an Earth ship.
The second Universe is the One we see in
Where No Man has Gone Before. In this universe Spock has a human ancestor.He fears people with ESP. Kirk's middle initial is R and was a stack of books with legs. Sulu is a physicist. The Enterprise is an Earth ship
The Third Universe is the one we see in
The Corbomite Maneuver. In this Universe Uhura is in the Command division. Vulcans are called Vulcanians.
The Fourth Universe is first seen in
The Enemy Within. In this Universe Uhura is in Operations.
Universe Five is first seen in
Charlie X. In this Universe the Enterprise is an Earth ship operating under the authority of the United Earth Space Probe Agency
Universe Six has the Enterprise operating as a part of Starfleet and first appears in
Tomorrow Is Yesterday. Star Trek takes place in the 22nd Century.
Universe Seven originates in
A Taste of Armageddon, it is very similar to the Prime and the Enterprise works for the United Federation of Planets.
Space Seed establishes this version is set in the 22nd Century.
Universe Eight is an odd one. It takes place in the 27th Century and debuted in
The Squire of Gothos.
Universe Nine is probably the Prime Universe. It starts in "Errand of Mercy".
Universe Ten is the TMP universe. In this universe the events of TOS are fictionalized versions of reality.
Universe Eleven is the TWOK+ universe. It might be the prime. Though if Kirk has no brother as implied in TFF, it might be a new universe.
Universe Twelve is the TNG early season one universe. It takes place some time after 2378.
Maybe I should stop here.