Want to start with Gutenberg right now? Really easy. Only install the Gutenberg plugin and try creating a new post.
This blog post will be more detailed soon.
Start with your existing WordPress website or blog
Only install the Gutenberg plugin, but care for a up-to-date WordPress installation and make a backup before. If it is a live platform, you better make a copy and do it there. Or better take the easy way …
Start with a new WordPress installation
Install WordPress on your webhost or local system and add the Gutenberg plugin.