How can you learn to truly understand League

I recently got to Platinum V maining mid. I knew it was going to get increasingly harder as I went up the ranks but it seems like as soon as I hit Plat I hit a wall too. I am wondering if there is some site or some helpful players out there who are way better and more knowledgeable than me to help me understand how to play league better.

Edit - Some of the things I know I am bad at. My mechanics at csing are marginal at best, averaging around 6.5 ro 7 a minute. My laning phase is my biggest weakness. From what I can tell, I have a lot of bad habits from climbing through silver and most of gold that I just got away with and now I am being punished for making those same plays. At the moment I am not sure how to change up my play style to be a better laner, basically I am having a horrible time being able to poke, so then I shove the wave to their tower, and then no matter where I put my wards the enemy jungler ganks and I die.