Even if aliens are real, it's still IMPOSSIBLE for them to travel from one galaxy to another and make their way to our planet. There is a natural speed limit for everything that exists in the universe, which is the speed of light. 186,000 miles per second is the fastest anything can go. It would take infinite energy to accelerate anything other than light to that speed. Andromeda is the nearest galaxy to our own and it, alone, is more than 2.5 million light years away already. Other galaxies are even billion light years away so it's impossible for an alien aboard the fastest-travelling spaceship to cross even a fraction of that distance in its lifetime.
Even if aliens are real, it's still IMPOSSIBLE for them to travel from one galaxy to another and make their way to our planet. There is a natural speed limit for everything that exists in the universe, which is the speed of light. 186,000 miles per second is the fastest anything can go. It would take infinite energy to accelerate anything other than light to that speed. Andromeda is the nearest galaxy to our own and it, alone, is more than 2.5 million light years away already. Other galaxies are even billion light years away so it's impossible for an alien aboard the fastest-travelling spaceship to cross even a fraction of that distance in its lifetime.
Life is rare. Intelligent life is even more rare. If ever there is intelligent life out there in the Milky Way aside from our planet, chances are they won't find us from the 100-400 billion planets within our galaxy. It's like looking for a needle in a bundle of hay.