"Are we alone in the Universe"
no.
HOWEVER, the distances are so HUGE that we might as well be. It takes YEARS or even lifetimes for light to go from one star system to another. The best that we can realistically expect would be some type of 'bulletin board' system for communication, and a long, long time between post and reply.
remember those from the early internet?
Surprisingly, only recently "breakthrough starshot" was announced!
What is not so long ago we thought - the future, coming true in our lifetime!