A Lunar Eclipse is a Full Moon that is so precisely aligned, the Moon passes through the Earth's shadow cast by the Sun. This precision makes the Full Moon extra powerful. This precision happens when the Full Moon is conjunct the Lunar Nodes, within about 18°.
When a lunar eclipse is visible from your location, it happens at night. It's okay to watch a lunar eclipse without any eye protection (it's the solar eclipse that can cause eye damage). When it's a total lunar eclipse, you'll see the Moon turn dark orange or red. A partial lunar eclipse may just turn a bit darker on one side of the Moon. The eclipse typically lasts for several hours and you need to be in the right place on Earth to be able to see it. Find out more about the astronomy of eclipses.
The New Moon just before or after a lunar eclipse is always a Solar Eclipse. Eclipses typically happen twice a year, about 5-5½ months apart. However, sometimes there are 3 eclipses in a row – lunar-solar-lunar or solar-lunar-solar. In that case, the two of the same type are usually partial eclipses.
Eclipse season is usually an intense time of the year when many changes take place. The house in your natal chart where the eclipse happens may under go changes or issues may arise that need to be dealt with. Eclipses have a reputation for being harbingers of bad news, but more often they will mostly just bring some intensified or dramatic energy for a short time. On the other hand, they can sometimes set changes in motion that play out for weeks, months or even years, depending on how big the changes are.