Couchbase GUI for exploring data
Just in case someone else comes across this needing help... the Couchbase UI is both command line and web-based, the latter of which is typically running on port 8091.

So, for example, if you've installed it on your computer, it would be http://localhost:8091/

If Couchbase is installed elsewhere, say IP 192.168.1.101, it would be http://192.168.1.101:8091

This is covered in the Couchbase 3.x post-install tasks as well as the post-install tasks for Couchbase 4.x.