yeah defiantly learn how to write songs even if there just basic on piano so you have some song writing skills and music theory/idea foundation and then as your making your tracks you will learn the techniques as needed for mixing sound design etc, but i wouldnt just focus on learning one thing kinda get an idea of the different things you will need to learn so then you can apply them properly. which would be in my opinion song writing,basic music theory will help you alot if you have no music background, learn a daw and stick with it for a while examples would be fruity loops,ableton,logic etc. and then if u got the money get some 3rd party vsts like sylenth1 or any other synths and learn them plus mayb some effect plug ins if you want, there is so many. learn mixing techniques, like stereo imaging and using volume and reverbs, to push sounds around and other techniques like haas effect all help also eq techniques to make room for other frequencies in the mix. just learn the different effects you can do and apply them in a way which sounds good. just make sure to have fun thats the man thing as your learning and just take it a day at a time and you will get there i cant think of anymore basic things but just ask