You are tripping.
Despite Star Trek and Star Wars, interstellar travel is impossible for either us or the aliens (who are probably out there somewhere).
No one can approach the speed of light. Maybe you might make 0.10%. The closer to the speed of light (relative to your departure point) the exponentially amount of propulsion is required. At the speed of light you’d need an infinite amount of propulsion. The more propulsion requires more fuel, the weight of which increases the spacecraft’s mass which makes it more difficult to move forward. It’s a self-defeating mechanism. To achieve the speed of light you’d need infinite mass, which would not move a centimeter.
That’s the gist of it all.
Aliens are real (we think). We haven’t detected them yet, but although one day we might expand throughout our solar system, travelling to other stars will remain impossible.