Learn SQL and data modelling. The Data Warehouse Toolkit by Ralph Kimball is a good introduction to data warehouses and dimensional modelling. It's not a universal model for data warehouses, but the core concepts remain the same among different implementations. This should give you a good basic understanding of the basic concepts of data warehousing.
I know Reddit isn't exactly popular here, but their business intelligence community is quite active. It might be a good place to lurk and gain some insights.
Best of luck! :)