A key part is to start simple. A basic outline is this.
- Learn what your champ can do
- Learn how your lane works
- Learn how to play your lane
- Learn how to win the game
In general, it starts very specific and grows very broad. I'll break down each step for you.
- Learn what your champion can do.
This is the easiest to figure out. Riot gives you descriptions, patterns, numbers, training modes. EVERYTHING you could need to learn a champion. It doesn't really matter the difficulty of the champion as you can take as much time as you need to learn it. Note, however, the harder the champion is, the longer you might need to get the hang of it.
For the sake of simplicity, I'll use Ziggs as my example.
Ziggs is an artillery mage. This means mainly uses his abilities from a long range. He scales with ability power and deals magic damage. His passive enhances his autoattack with bonus magic damage based on your AP. His Q throws a bouncing bomb that explodes on the first enemy hit dealing magic damage based on your AP. His W throws a satchel charge on the ground that will detonate after a few seconds or if you recast it. It deals magic damage based on your AP and knocks back enemies or launches you away from the charge. It can also execute towers. His E deploys a minefield that deals magic damage based on your AP to any enemy that walks over it. His R is a long range bomb that deals magic damage based on your AP, dealing increased damage to enemies in the center.
Riot tells you all of this. You can practice using his abilities in practice modes. You can also practice other mechanics with him. Such as using his Q ability while in the air from you W charge. You can learn ability ranges and relative damage outputs. You can also learn about your weaknesses. His main issue is his lack of mobility. Without your satchel charge, you have no escape.
Now that you know what Ziggs does, let's look at what your lane does.
- Learn how your lane works.
Mid lane is generally where Ziggs would go. Mid is the center of the map and is just as important as it would sound. The mid lane can easily set the pace of the game. The goal of midlane is to either get an advantage and then roam and give that advantage to you teammates to get them ahead OR to farm and grow strong to shine in the late game.
Ziggs is the first. Ziggs is best at grinding down champions and towers using his abilities and then going to side lanes and doing the same thing. With this in mind, you can move tot he next point.
- Learn how to play your lane.
Because you are highly immobile, you generally play safer. Based on the matchup, you may or may not have a winning lane. If you have a winning lane, you can play more forward and apply damage whenever the opponent tries to farm. Ziggs is best at whittling down his opponents rather than all-ining at once. This means you just need to keep harassing the enemy until they leave or die. You can then place vision for you jungler to play more around you.
If you do not having a winning lane, you must play very safe. You have to play back so that the enemy cant kill you. You must also be sure to place defensive vision so that you can still safely farm.
After figuring out how you can win/survive your lane, you can figure out how to win the game.
- Learn how to win the game.
This seems like a pretty obvious question. Clearly, you just destroy the nexus. Easy Peasy. The trick, however, is learning the EASIEST and BEST ways for YOU to win.
Ziggs is good at poking enemies down and destroying towers. So, you can setup good sieges with your team and poke the enemy down until they must forfeit their tower. He also has good wave clear and can defend towers very easily. You can simply slow push down towers or stall out games until you and your team reach item breakpoints and/or win better fights.
I really hope this helps! Please ask any questions you may have and I'll be happy to answer as soon as i can![sg-ahri-2]
Also, sorry this turned into a wall of text..
Fizz Mid 
Taric Support 
Ziggs 
And Yasuo 
