you shouldn't be focusing on anything really. just 15-30 min of kz a day will solve most issues and help ya improve. doesn't matter how much u fail 1 jump just try to go thru the map as quick as possible.
the peek at ramp was poor indeed, but knowing how to peek every corners comes with time and experience, so don't bother with that yet.
yprac maps and ffa helps with angles, preaiming, and peeking corners, but i wouldn't bother with those things just yet, since we all saw your enemy's level of play. :))
also as a tip, try to always think where you want to go and what you want to do before doing it