If youre low elo and are trying to learn and climb, I would suggest you to pick a one champ to be your main and a second alternative. For your main I would recommend Jax. He is extremely op and easy to play. Just master the champ, and by that I mean, play A LOT, learn the matchups that you are strong and weak and learn how to take a lane pahse when you are in a disvantage. Also, somehing that can help you climb easily is to learn the wave control, just search for a good youtube video of it and start applying in your game. GL