It really isn't for beginners, because this game thrives on experience as well as skill, everyone gets better over time after learning everything possible with every champ. How do you do that? Play the game an insane amount. I know it feels like you have been playing forever trying to get to level 30, but trust me that's not even a comparable amount to the people you have been playing against. They have seen plenty and know how to beat you in multiple ways. To be fair this season is probably the WORST to learn the game considering how much more snowbally the matches play out.
I'm sorry for anyone who calls you a noob/random insult/etc. for playing poorly during this time but just try your best and keep at.
TL;DR
This game is about experience, skill with mechanics, and good decision making. All can be acquired with time.