Rails and Python are good back end languages to go for, especially if you're going to be working with web technologies. If you look at takeaways from Stackoverflow's annual survey (https://blog.zipboard.co/developer-trends-to-watch-out-for-a0b11c49dbec) you'll see that Python has overtaken PHP this year. Also Python can be big help in Data visualization, if you need that.
And JavaScript is a good resource to know without a doubt. Depending on what technologies you are working with and what project you are building, I'd say start with one of these three.
Rails and Python are good back end languages to go for, especially if you're going to be working with web technologies. If you look at takeaways from Stackoverflow's annual survey (https://blog.zipboard.co/developer-trends-to-watch-out-for-a0b11c49dbec) you'll see that Python has overtaken PHP this year. Also Python can be big help in Data visualization, if you need that.
And JavaScript is a good resource to know without a doubt. Depending on what technologies you are working with and what project you are building, I'd say start with one of these three.