I believe if life is common than there must of been at least one group of aliens that at least attempted to colonize it self everywhere in space?
Unless humans are a extreme anomaly and that most other aliens don’t really care about space exploration, and just focus on their home planet.
We kind of have: Oumuamua, UFOs, and structures on the back side of the moon. Check out the book Ingo Swann - Penetration. Also watch the documentary Third Eyes Spies those two go well together to lend credibility to Ingo Swann. You won't be disappointed. Another interesting personal documentary is Walking with the Tall Whites There are way too many other sources that can be mentioned, including declassified US government documents about UFOs. There is overwhelming evidence that aliens(and their UFOs) regularly visit earth and have had contact with the US government since Eisenhower, and Reagan was informed about it too.
As for other civilizations, many are in different dimensions not yet accessible through our technology. The closest civilization in our dimension, according to Bashar the ET, is the Bernard Star civilization, which has a development similar to our renaissance era, and according to him, they will be the first civilization we will eventually visit.