Which planet had the first moon?

Most of what we have available on the subject of the first moon in our solar system relates to the timeline of the formation of the first planet.  The idea is that the first moons were the ones around the first planets.  The first planets to form in our solar system were the Gas Giants.  They formed even before the Sun began nuclear reactions at 50 million years after the beginning of the 0.0-year Pre-solar Nebula Era, according to NASA's Goddard Space and Flight Center.  At about 10 million years after 0.0-year, the gas planets Jupiter, then Saturn formed during the Gas Giant Era. Jupiter and Saturn both have multiple moons (with Saturn perhaps in the process of birthing a new moon).  Jupiter has no lack of moons, both large and small, with 14 large ones alone. Two of the most important of Jupiter's moons are Europa and Ganymede, both about 4.5 billion years old, which is about the same age as Jupiter itself. Saturn has an abundance of moons as well, with 53 that are classed as "official" and 9 that are classed as "provisional."  If it is correct to theorize that the first moon (or simultaneously appearing moons) appeared with the first planet, then it can be said that the first moon or moons appeared around Jupiter because this gas giant, Jupiter, was the first to form in our young solar system.

Of incidental interest is that in 2012 a new planet was discovered in a solar system some 375 light years from the Earth.  HIP 11952b and HIP 11952c are two dual planets that have been established at around 12 billion years old.  There position, of course, exceeds the galactic limits of our solar system, but this dual planet system is older than Earth by about 8 billion years, our solar system being around 4.6 billion years old.  It is thought that these two planets came into existence about a billion years after the Big Bang.  If these extra-solar system planets have moons, then their moons could have been the earliest moons in our locale.