Try to learn at least some of every role. Seriously, itll save you in the long run. Just take some time and play a bit in each role. Yes, even learn support. Every role has its perks, and downsides. Learning every role also have other benefits like learning their weaknesses, their strengths, etc etc. So if you havent yet, go and learn the roles.
Calabok3 voteshow to deal is to dodge.
His Dinoboy1 votesgood point. but why not just play a champ that can play all roles? 
AFilthyCaitMain1 votesI know thats obvious sarcasm, but you should never just play one champ, let alone in one role. Playing multiple champions will increase your general knowledge of the role and game. Say you only play Yasuo mid and nothing else. Well you know stuff about mid, but not as much as you COULD know. You know more about Yasuo than you probably do mid. So playing multiple champions will increase your overall knowledge.
His Dinoboy1 votesPlaying and learning one champion to its best ability is apparently one of the best ways to climb, but i agree that playing one champ limits your knowledge.
AFilthyCaitMain1 votesIMO the best way to climb, is to build yourself base knowledge before even TRYING ranked. Learn every role, be confident in your ability, be able to turn games around, gain some game knowledge, find some of your favorite champs, and so on. Going into ranked without most of these things is basically asking to never climb. If you have solid base knowledge to work of of, youll be able to climb and learn way easier.
His Dinoboy1 votesi agree but norms are horrible for learning imo. they are ff 20 fests with pre level 30 players. also before i played ranked i thought full crit renek was broken because i would always win lane, get fed, and two shot other melees because of my insane lead. yeah you can learn from norms, but it isn't good at showing you what works and what does not. another example is how im able to carry norm games with ap ww mid. sometimes even getting 30 + kills
AFilthyCaitMain1 votesBut its better to at least learn something than to go into ranked, lose all the time, get frustrated because you cant win, etc. From playing norms, ive gotten way better at the game. I usually have an ok score, when i used to feed hard, i am heavily familiar with some champions kits (Which is useful af when playing ranked), and so much more. It my not seem like youre learning, but you are.
BLACK REALM GOD1 votesor! learn how to play your main in every role well enough to compete with every role.
AFilthyCaitMain1 votesThat can work in lower ELOs, but that probably wont fly higher up as they will probably know how to easily kill you in a role you shouldnt be doing well in.
BLACK REALM GOD1 votes"can" "probably" "probably" "fly"
your words are things.
Shuyin1781 votesAlternative if you're bad at the game
stay out of Draft/Ranked and just play ARAM or Blind