your best way to improve is to analyse games history and think what you could have done better.
not only your own games, but also games from top ladder players.
we do this livestream event every so often called WGL where we analyse games happening on a realtime tournament, you can find the old recordings here:https://www.youtube.com/playlist?list=PLjxyPjW-DeNUNWCqlOchKmibziGO4Kofr
if you post on the forum specific games with specific questions there will certainly be people discussing it.
once you reach the level required for the realtime ladder, that's also a decent source of competitive games (more competitive then the random auto-game atleast).