Hi,
If i go ahead and delete is there going to impact any other DB. Please advise
(1) A backup is for specific database which mean that the answer is no. Delete a backup dose not impact other database backups
(2) Moreover, when you are using Azure SQL Database then there is no relations between the databases other than logical (management) relation. You should understand that what you call "sql server instance" is in fact only a logical instance and not a real instance (application which give you the feel and look which familiar when you manage on-premises instance.
Azure SQL Server logical instance can include multiple database which are physically attached to different instances in different machines. Moreover, Azure SQL Logical instance can include databases from totally different type like azure sql database and synapse databases.
So, if there is not real relation between the database, you can understand why managing backup of one is not impacting another one