(this guide will be written as if the ad carry is Graves,ezreal, or corki) there is often no need to go aggressive in lane be4 lvl 3-4 because your ad carry will do more damage if he have his quickdraw, valkyrie or arcane shift, because then he can use your passive for it full potential. when engaging on the ad carry, try to land your E and Q be4 you ult. to make this easier: try to cast your E 0.3 sec be4 he is about to kill a creep, this works if you are engaging with your ult aswell.

your most important role in a teamfight is the engaging because you are the most important camp at that time(unless you have a malphite on your team or something like that). after you have ulted as many enemies as u can, go in with your E(together with your team) and exhaust theire ad carry. you need to practis if you are gonna be good at this.

talk to your team. if the jungler is going for agis u should go zeke's and shurelia's. if someone on your team gets shurelia be4 you, u should go zeke and agis. just get normal support item, it's not a big deal.