To the first problem :
A lunar eclipse Occurs when the Moon passes directly behind the Earth, so only when the sun, Earth, and moon are aligned ; occur at full moons.
A solar eclipse Occurs when the Moon is between Earth and the Sun; Occurs at a new moon.
Lunar eclipse are more common. ---------------------- For the 2nd part: The gravitational attraction of the moon causes tides. One importance is Commercial and recreational fishermen use their knowledge of the tides and tidal currents to help them improve their catches