Getting Started with Writing Queries
This tutorial will teach you the basics of writing queries against the Stack Exchange Data Explorer (SEDE), starting from "hello world" and working up from there to some interesting multi-table queries. We don't assume you already know SQL or database concepts. We're also not setting out to teach you everything you can do with SEDE queries. You can do a lot with just a few basic SQL concepts and the database design, and then you can explore further on your own.
We hope that the combination of this tutorial and reviewing existing queries will give you the tools you need to explore Stack Exchange data with your own queries.
But First: A Very Brief Introduction to Databases