Hello Mark,
from that what you have written I assume that you are using the HANA instance on the HCP trial landscape. On such an instance you have several limitations. For example you cannot create a new schema.
But you should be allowed to create packages within the package <xxxx>trial -> <your hana instance> (not directly within the <xxxx>trial package).
There is also a specific NEO schema for your DEV user which you can use. You can determine the name by a select on table "HCP"."HCP_DEV_METADATA".
Check the information given at SAP HANA Cloud Platform - Using a Trial SAP HANA instance.
Best Regards,
Florian