You seem alright, you tried to give context with the champs you main, but still. It's agonizing to see all the "give tips on be good" just generally asking how to be good at the game. Anyways, I'll try to give some tips :)
Judging by your champs, I guess you play some Jungle. First thing is, do you have runes? get them. Use the masteries with effects on jungle minions. (I know, incredibly basic stuff, but also important if you don't have them)
If you are playing warwick, try to farm hard until 6 then gank lanes whenever your ult is up.
If you are playing Xin Farm hard until devourer becomes Sated Devourer and then gank and fight as much as possible because you are only going to fall off from there.
As Zac, you want to gank early, like level 3, max E, farm a little, but mostly just clear your buffs and keep ganking.
Both WW and Xin can solo drag once they get their finished jungle item. Zac probably needs help.
You say you play all lanes at least a bit so:
As top lane you want to apply pressure constantly so your opponent can't roam. If you find your self with the lane pushed into their tower and a good amount of health, try taking scuttle or ganking mid. Use teleport to gank bot lane or help fight over dragon if that happens.
As mid lane you want to poke your opponent out of lane so you can farm and roam. You can go to top or bot, whichever looks easier to get kills.
As bot lane you want to take your tower ASAP and then help mid and control drag.
All lanes, you want to farm, ward, and get kills where possible.
I am plat 5 now, I started... a year and a half ago. Idk when I got "good" at the game, it has been a slow consistent process of learning.
As far as understanding where you are on learning the game, If you play ranked and are bronze, you don't know how to play the game. Not to be mean, you just don't know some stuff. Normally this is things like: warding, ganking, drag and baron control, pushing towers. I would say if you are gold, you have a grasp of all the important concepts of the game. If you are confused by my skipping of Silver, it's just that's an intermediary between bronze and gold.
hopefully these tips were somewhat helpful. I know they aren't exactly a guide on how to be gold, but I hope they do assist you in learning the game and increasing your skill and enjoyment of it.
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Sorry if my format of text kind of throws you off. Thanks for reading, hope I didn't waste your time.
