Have you setup the environment and added the networkId and organizationId correctly? The org and admin calls are organization wide and only need the API key, the other calls you're trying to access may need the organizationId and networkId.
My advice, start with getOrganizations call, that only needs the API key (I think that one's working already).
Choose one of the returned organizations and add it's organizationId to your environment.
Then you can execute the getOrganizationNetworks call which will list all networks under the organization.
Choose a network and add it's networkId to your environment.
Go from there.
You environment should look somewhat like this at the end: