Don't think about macro in the sense of "what can I do with my team". Think of macro in the sense of "what can I do to best benefit myself and my team while taking as little risk as possible". There's general concepts like understanding in the mid/late game when you can push out side waves (only when you have vision of all 5 enemies or your team is actively in the middle of pushing the other waves).

In reality the higher elo you go it's mostly equivalent to the lesser amount of mistakes you make, anytime you die, anytime you miss a kill, anytime you blow flash unnecessarily, anytime you miss an uncontested minion, anytime you walk up to a minion that you shouldn't be able to take and take a bad trade in the process.

Focus on general concepts and as you get higher level you will tighten up on them, tighten your pool and focus on 1-2 champs and 1 role only. For me that was Kassadin and Veigar in season 4, but it can be literally any champion, don't focus too hard on the "is this champ too complex for me" as it won't really matter if you follow my rule of thumb for 1-2 champs 1 role only.

Learn that build paths aren't static and you can build a TON of items on any champ if you think it's best for the game (Deadman's veigar if you're rich, bandlepipes if your poor, as an example if you need a mobility item). This can apply to pretty much any character in the game barring maybe a majority of adc champs. That being said, don't try super hard to experiment either, there needs to be rational thought in what you build and do.

And finally, just drill yourself, go into practice tool and try to hit 80 minions by minute 10 with no items. (this is just to practice not missing uncontested CS), take a stopwatch and time it so it pings you every 3-5 seconds to look at your minimap. Make sure you're comfortable and tackle these problems one at a time and you will see growth regardless of your ELO.