Connecting to your Hyperscale database is exactly the same as any other Azure SQL or SQL Server database – for example, you can use SQL Server Management Studio or Azure Data Studio. That is the exactly point. Hyperscale provides capabilities not found in other cloud databases such as scale and query performance, but it has no impact on your applications. If you do an in-place migration of a SQL database that is already on another service tier to Hyperscale, the connection string would not even change. Your application does not have to be changed and it will benefit from bigger scale and improved query performance. And who does not like the extra scale and query performance?
This post covers the basics of database creation but does not go much further into it than that. Jeroen does promise a multi-part series, however.