Comment by wikunia

Okay for coding I what say: practice practice practice :D I personally learn best when I have an idea and I want to implement something specific. Can be big or small. Best are the ones which are very extensible. What I do as a mentor is to review code and give feedback. You probably don't wanna learn julia though. You can get some starter feedback at exercism.io Maybe you can ask there as well if someone wants to mentor you for some cash.