Azure Cosmos DB - Understanding Partition Key

I'm setting up our first Azure Cosmos DB - I will be importing into the first collection, the data from a table in one of our SQL Server databases. In setting up the collection, I'm having trouble understanding the meaning and the requirements around the partition key, which I specifically have to name while setting up this initial collection.

I've read the documentation here: (https://learn.microsoft.com/en-us/azure/cosmos-db/documentdb-partition-data) and still am unsure how to proceed with the naming convention of this partition key.

Can someone help me understand how I should be thinking in naming this partition key? See the screenshot below for the field I'm trying to fill in.

In case it helps, the table I'm importing consists of 7 columns, including a unique primary key, a column of unstructured text, a column of URL's and several other secondary identifiers for that record's URL. Not sure if any of that information has any bearing on how I should name my Partition Key.

EDIT: I've added a screenshot of several records from the table from which I'm importing, per request from @Porschiey.

Honestly the video here* was a MAJOR help to understanding partitioning in CosmosDb.

But, in a nutshell: The PartitionKey is a property that will exist on every single object that is best used to group similar/related objects together.

Good examples include Location (like City), Customer Id, Team, and more. Naturally, it wildly depends on your solution; so perhaps if you were to post what your object looks like we could recommend a good partition key.

EDIT: Should be noted that PartitionKey isn't required for collections under 10GB. (thanks David Makogon)

* The video used to live on this MS docs page entitled, "Partitioning and horizontal scaling in Azure Cosmos DB", but has since been removed. A direct link has been provided, above.