Once you’re good enough on those things the question is what to learn next? And I’d strongly advocate for taking a weekend to learn SQL. Mode Analytics SQL School is a really great, approachable way to learn SQL. It’s most focused on writing ad hoc queries for analytics purposes, but that’s totally fine.
So seriously, why SQL?
Well first, it helps you understand deeply how relational databases actually work. This is unbelievably helpful when talking about the way a data structure is going to be set up in your app. It’s also super helpful to understand what it’s going to take to generate a particular set of data for some view you are considering. Knowing the basics of joins, wheres, and counts is fantastically helpful.
No seriously, I can’t stand it. I’m pretty much willing to go way way far out of my way to not have anything to do with it. And if you’re dealing with big sets of data, and you’re trying to do high level exploration of what’s going on in it, SQL is one of the fastest ways to do that. Python also has some great tools for exploring data, but understanding basic SQL concepts will help.
A quick and dirty SQL setup
Once you’ve spent time with Mode and gotten familiar with the lay of the land, you may get to the point where you want to play around with your own data. The fastest and easiest way I’ve found to do this is postgres.app and PG Commander. Once you’re up and running with those two, you can use Postgres’ COPY command to load a .csv into a database you’ve prepared (just go with varchar, you’ll thank me later) and you’re off to the races.