I don't have any musical background, except a tiny bit of guitar back in the day, so when I started LSDJ I was in the same boat as you (heck, I still am), but here is kinda what I did and I found that it helped out a lot:
- Like other people have pointed out, looking at other peoples .sav files is a great way to learn how to make certain sounds and how certain note progressions and the like are incorporated into a song.
- I'm not sure if this has been pointed out, but I strongly suggest you read the full LSDJ manual, and keep a copy close at hand for reference. I don't know how many times I have looked up commands in mine to refresh my memory and it is a good idea to know what all the commands do and how the program works so that you can partially understand how the sounds are being made and have more control over them.
- Again I think this was already pointed out, but watch lots of youtube tutorial videos and there quite a few tutorials on the web if you just do a quick google search.
- More than anything else though you just have to keep working on stuff: try new settings for instruments, change your not progressions around, play with panning, chords, etc. Just make stuff that you think sounds good.
I'm sure I've just re-hashed a bunch of stuff in this thread but it was a tl;dr moment, but I would say overall just keep plugging away and just do whatever works for you and that you like the sound of