Connecting to a database is going to depend mostly on what type of database you are connecting to and if you have the authorizations to connect. For SQL Server, I use and ODBC connection. First on the input tool, set up a connection and select "Data Sources", and at the top of the screen select the Microsoft Sql Server ODBC connection. After selecting "New", you can set up the connection. The name isn't relevant, but the ODBC DSN is. Click on the gear next to it and add a system DSN. You might want IT help to do this step as it requires the name of the server and some connection settings that vary between companies. Once created, you can connect and select the database table to retrieve data from. Also, once it's connected, you can use in-DB tools as well. Once you get that far, we can likely answer any questions you might have.
If you manage to get your data to Alteryx, it will work the same as any other data input. Without some example data, it is difficult to answer your specific question on the template. Is this an Excel template you are wanting to populate?
