lane
you can swap out Grit for one of the lane optionals if needed
lane options
usually just go with Extra Regen, but feel free to try things out
mid
Hunters Aura ASAP, giant powerspike you will be thanos, Bullet Resist Shredder also giga broken, enemies you 1v1 will explode because of how much bullet resist you shred off of them
optionals
same old, you probably wanna get 1 or 2 of these going every single game, not going to list every example because it would take me 5 years but easy ones are infernus/mirage/bebop = dispel, talon = counterspell, that kind of thing. if you are learning the game you will learn as you play more
late
I usually just get Scourge as a T4, but if needed you can also swap that out for Ethereal Shift, like if you are getting full ccd you probably want eshift
more optionals
same as other optionals, not going to write about every item but compress cooldown if you need more ults (somehow), cold front is also cool, all in all you just have to optimize for your investments as much as possible, so watch for that