You must be an Azure Databricks account admin to getting started using Unity Catalog.

The first Azure Databricks account admin must be an Azure Active Directory Global Administrator at the time that they first log in to the Azure Databricks account console. The initial account admin can elevate others as account admin to delete the privileges to other users as mentioned in the below document.

https://learn.microsoft.com/en-us/azure/databricks/administration-guide/account-settings/account

https://learn.microsoft.com/en-us/azure/databricks/administration-guide/account-settings/