Why doesn't the moon always follow the same path? Or why aren't the moon's apoapsis and periapsis fixed? I have seen many times that the moon doesn't follow the same path. Sometimes the moon gets very close to earth which is shown in the news. If the periapsis of the moon is soo close then why doesn't a super moon occur every 27 days? And if the moon is inclined at 5.1° so how can more than 2 eclipses occur in one year?
The Moon's orbit about the Earth is only approximately elliptical. The Moon's orbit precesses both axially and nodally, and the eccentricity of the Moon's orbit varies.

That the Moon's orbit precesses axially means that perigee sometimes occurs when the Moon is close to new, sometimes when it is close to half-full, and sometimes when it is close to full. Supermoons occur when perigee occurs close to when the Moon is full. The variation in the eccentricity means that apogee distance and perigee distance vary considerably.  Super-supermoons (my term) occur when perigee occurs close to when the Moon is full and when perigee distance is much closer than nominal. While supermoons occur about three of four times per year, super supermoons occur only once or twice a year.

With regard to eclipses, suppose that at the time of a full Moon that the Moon's orbit about the Earth is close to being aligned but not exactly aligned with the Earth's orbit about the Sun. This means that a month later, the Moon's orbit may still be close to being aligned with the Earth's orbit about the Sun. The large size of the Earth's shadow makes it possible for lunar eclipses to occur in two consecutive months.

Eclipse seasons, the times during which lunar eclipses and solar eclipses are possible, are about 34 days long, a bit longer than one month. This means that if a partial lunar eclipse occurs just as an eclipse season starts, a nice solar eclipse will occur half a month later, and a partial lunar eclipse will occur another half a month later. Similarly, if a partial solar eclipse occurs just as an eclipse season starts, a nice lunar eclipse will occur half a month later, and a partial solar eclipse will occur another half a month later.