If you want my opinion I would just play normals until your skill level is around gold then switch to ranked and the games will be really easy and you will climb. I can guarantee that the reason people don't climb is because of player skill OR lack of time and almost never from bad luck. I recently made a smurf that is plat 5 playing with plat 1s in about 50 ranked games I have a 75% win rate or something close to that on it. I went 7-3 in promos and was placed into silver 1 and climbed to plat in the other 40 games.
My main is diamond 5 so it makes sense that I am now playing with ~plat 3 to 1 on my smurf since im playing assassins which I was previously not as good at as I am at mage type mids and because my champion pool and rune options are much more limited.
You just need to learn to: trade, watch the map, cs, make good dragon and baron calls and have good teamfight positioning. Obviously none of this is super simple or the game would be boring and not have the levels of mastery that it does have. But if you play to improve you will climb and if you only play to climb you probably won't learn much and the losses will be much more frustrating than they have to be.
