To list the available databases, use the following command:
$ show databases
name: databases
name
----
_internal
devices
... list of your databases
You can connect to one specific database:
$ use <database_name>
By using a single database, the scope for each subsequent query will be limited to that database. This means that you won't have to explicitely provide the name of the database in each subsequent query.
Do note that by design the SSH connection remembers the current scope, but not all client SDK's are guaranteed to have this available as well.