The query below lists all the schemas in the Azure SQL Database. Schemas include the default db_* , sys, information_schema and guest schemas.
If you want to list only user schemas, use this script.
select s.name as schema_name, s.schema_id, u.name as schema_owner from sys.schemas s inner join sys.sysusers u on u.uid = s.principal_id order by s.name
Here is a view of database schemas in SSMS: