The appearance of an alien from another planet would vary greatly, as it would depend on the planet they come from. They could have a humanoid form, with two arms and legs, or they could have a completely different body structure. Some may have fur or scales, while others may have no visible physical features at all.
Communication methods for aliens from another planet may also vary. It is possible that they may have a spoken language, similar to ours, or they may use telepathy. Some may even communicate through a series of clicks or other sounds. It is also possible that they may have advanced technology that allows them to communicate with us in a language we can understand.
It is likely that aliens from another planet would have advanced technology, as they would have had to develop it in order to travel through space. This technology could include advanced forms of transportation, communication, and other discoveries that we have not yet made on Earth.
The reasons for an alien's visit to Earth would depend on their individual species and motives. They could be explorers, researchers, or even refugees from their own planet. Some may also have hostile intentions, while others may simply be curious about our planet and its inhabitants.
This is a difficult question to answer, as it would depend on the individual alien and their intentions. Some may be friendly and want to establish a peaceful relationship with humans, while others may see us as a threat and act accordingly. It is important for us to approach interactions with aliens from a place of caution and respect.