Do not colonize other planets. They suck. They have all the downsides of space habitats (needing sealed environment, etc), while also adding more (breaches now let in toxic dust instead of vacuum, cannot control gravity via spin, etc).
Just build O'Neil cylinders. If you can't do that, maybe work on stabilizing the ecosystem we evolved to live in. Nowhere will ever be better than here, folks.
There is so much about the cylinder concept that hasn't been thought out, it's just an insane undertaking even if it could all work. It started as a joke, but hey maybe one day someone will prove it to be a better reality.