I am trying to answer your questions:
- Your boss needs to perform some Account administrator task including associating credit cards with the account. Please read here for a list of tasks.
- Here you will steps to create an Azure SQL Database and how to create tables on it.
- There are some fixed database roles in Azure SQL and one of them is the loginmanager role that allows to create logins and users that can access the database. Please read about this role here and how to add members to that role.
- Here you will find how to connect to Azure SQL to do administrative tasks and run queries, create objects (stored procedures, tables, etc.). Here you will find steps to connect to Azure SQL from SSIS. Here you will find how to connect to Azure SQL using Azure Data Factory (ADF) and copy data to the database. Here is a comparison of SSIS vs ADF to choose what is best for your organization. Finally, you can also connect from .NET apps to Azure SQL as explained here.