I've been relatively new to the game but there's one thing i'm really struggling with.
My main is Garen but I also play Olaf, Cho Gath, Tristana, Yasuo, Riven.
Sometimes I see people go like this: I'm toplane Garen, my enemy is Yasuo, so I buy this and this and this.
And when I'm against Teemo I have to buy this and this and this.
But how on earth do I know what to build against my enemy? I really have no clue lol. I usually just use one and the same build because I don't know anything else.