Invent warp drive, start colonizing!
There are lots of Class M planets. They visited a new one almost every week on Star Trek.
They even found a planet on which there was silicon based life, as opposed to the carbon based life found on earth. So there could even be life in forms we wouldn’t think about, such as silicon based life, out there in the cosmos.
Why haven’t aliens with advanced space travel come to Earth yet?
If they are that advanced, they must be conservatives.
They don’t want to infect their societies with socialism.