I've been playing since season 3 and I'm still only around Platinum level, you just have to play lots of games. I'd say that the biggest hurdle now has got to be learning all of the champions and their 4 abilities (+ their passives). It's really hard to know how to play a certain game when you don't know what a few champions do on the enemy team. The next biggest hurdle is gonna be all the items and learning how to build the champions you wanna play (It's also important not only to know what to build, but why you're building it). I recommend playing all the champions you can while learning and figuring out how they work and what they can do, if you're not comfortable going into normals with them there are always bot games and ARAMs to try them out in. Once you get these fundamentals down you can start learning about things like Macro and Lane matchups and so on. Also just remember that there's a mute feature for people that are being unnecessarily rude to you, and please remember that you're not a let down in these games, you're just learning and trying to have fun like the rest of us. Best of luck friend, I hope you get to where you want to be and I hope you have fun whilst doing it!