Even if you have a spaceship capable of light speed, where would you go? And what would you do when you get there? The reality is that outside of Earth even standing on another celestial body for a considerable time for humans is impossible, not to mention the trip itself. Just the isolation confinement for years will make you crazy. The practical and effective way of exploring space is by observation using sophisticated telescopes and sensors. For our solar system robotic missions are more effective than astronauts. No need to worry about humans limitations, robots can stay on the mission for years just feeding on sunlight or nuclear power. No need to come back home.
As for radio contact with aliens. That is the equivalent of someone in NY trying to hear a conversation in London with your own ears. And that is assuming the alien has it s antennas pointed to Earth, have a transmitter power of at least all the nuclear power plants on Earth, the same radio frequency and transmission originated at our reception time. Not to mention the language barrier.
Just like us any alien being will be closely attached to the planet enviroment that they are born and would very difficult for them to do interstellar travel also. It is in the same scale as an eagle trying to reach the moon.
Space is veeeery big and hostile for our life form. And space time is measured in thousands of years for our galaxy. If loneliness is when you can't reach or touch someone then we are alone in the universe.
Live long and prosper.
José