Re: Confused about SQL Server, Enterprise Gateway and publishing reports from Power BI desktop

 Regardless of whether you use gateway or not you will have to ensure data source is available online at the time of refresh. I would suggest you host sql server database on a server that is never offline and not your laptop. 

1. Schedule refresh will always fail if at that time laptop hosting data source if offline.

2. Once you install gateway on server where your sql database is and your report is published to power bi service, you can have to configure gateway first and then published datasets to use that gateway.