I'm relatively bad and new myself, but I personally have found that selecting a few openings and limit yourself on these will help build up a world that you are familiar with. As you encounter unfamiliar responses, go back after the game and see what went wrong and try to smooth out your strategy.
I have tried to limit myself on Sicilian variations as black, and queens gambit as white since it's comprehensive amounts of information available on these, and to me at least they feel aggressive \ sharp and I love when tactics come into play. :)
If it's in any way relatable to RTS like Starcraft \ Warcraft, openings \ build orders is what sets you up for the game and if these are sub-optimal, you will struggle in the mid to late game.
edit:
I also love tactics trainer and the coach. :) As an extra note, the computer analysis can be helpful provided for plat \ diamondusers, and you can also use the game explorer to "plot in" the moves and find your inaccuracies early on! It's really good.
I think this has probably been discussed before but would appreciate any feedback.
I find that doing the tactics trainer and just playing vs those better than me (which is pretty much everyone) are the most helpful in improving.
I have found that studying openings is a little over my head at this point because it's hard to see where they are leading.
Any suggestions for further improvement; at what point is serious study of openings appropriate?