Hello emilyjordan!! Great question! I certainly do think their is life out there! That is the whole motivation behind my research field actually – astrobiology is the search for life in the universe (we also do a lot to understand life here on Earth). Awesome huh?
Most likely if aliens are real they are microbial. The dominate form of life on Earth is actually single-celled organisms. A single teaspoon of common dirt holds any where from 1 million to possibly even 1 billion bacteria cells. This means there are more bacteria in a cup of dirt from your backyard than their are humans in the entire world!! Not only that but single-celled life can live in extreme climates on Earth where no other life can – ranging from deep in glacial ice, to super hot hydrothermal vents at the bottom of the ocean, to even 2 miles underneath the Earth’s surface. Microbes are everywhere! This has led a lot of scientists to think that most life in the universe might be microbial. Searches for life in our own solar system are certainly focusing on this! Microbial life of alien origin may be living in places like Mars, or Europa (a moon of Jupiter), or even Titan or Encleades (moons of Saturn) right now!!
As far as more advanced alien life – intelligent life like you or I, I have NO idea what they might be like. There is lots and lots of speculation, but we cannot know for sure until we possibly meet such a species. Which may happen one day but may not. It would depend on the planet they are from and the unique history of the coevolution of their home planet with its life. For example here on Earth, we have certain features because of our planet and its life. For one Earth didn’t have oxygen early on – microbes made it! So later we came along and breath oxygen. On another planet perhaps the history was different, so the intelligent aliens might be very different. As far as if we could be able to communicate with them. At first I am certain no, but I am sure we could figure it out. Actually SETI (the Search for Extraterrestrial Intelligence) researchers think about this a lot. Often they use human languages and animal communication to try to figure out how we can translate different modes of communication. For example, back in early human history – when europeans met the chinese they certainly did not speak the same language but they were able to find ways to communicate and learn the others method of communicating. So, my hopes are high!