You can download and run the latest version of Focalboard Personal Server with a single-line Docker command:
docker run -it -p 80:8000 mattermost/focalboard
Then open a browser to http://localhost.
or, to specify a port number:
docker run -it -p <port>:8000 mattermost/focalboard
Follow the steps in the setup guide to configure Focalboard manually.