The mid lane role is arguably the most difficult and impactful one in LoL. Here are five champions that give you a warm introduction to the role.
LeBlanc

LeBlanc is an ideal champion for players new to the mid lane because she has a little bit of everything. She has good range on her abilities so she can poke out her enemies, she has some crowd control so she can lock down pesky opponents, and she is mobile enough to run away from a bad fight or follow-up from a teammate’s engage.
Keep in mind that LeBlanc is rather squishy and takes some time to scale up to her maximum power. Because of this, players need to make safe plays early on until their jungler comes to help. Then, once she is strong enough, she can start one-shotting people with her powerful kit.
Ahri

Ahri may not seem like the perfect champion, but she has a lot of potential when played correctly. She is rather similar to LeBlanc, so she has many of the same benefits. She has long range on all her abilities, can engage or disengage from a fight as she chooses, and even has enough crowd control for her to be impactful on her own.
Another reason supporting Ahri is that she is mobile, even more so than LeBlanc, especially with her ultimate. This makes her a very forgiving champion for newcomers. If she overextends too far or needs that extra distance to reach an opponent, she can easily use her ultimate to get herself there as fast as possible.
Lucian

When playing Lucian, especially in the mid lane, it is important to know that he does not scale very well into the late game. Even if he has a sizeable lead, he can still stumble if the match goes long. With that in mind, players need to make the most of the laning phase so they can force their opponent into a position where they also won’t be very useful in the late game.
With his high early damage output, he can easily make plays once he hits his level two power spike. Getting an early gank into a Lucian lane is ideal, since it will give him a good footing to start off on, and then can turn his attention toward his allies to help them once he gets enough of a lead in mid lane.
Nocturne

Nocturne isn’t a typical mid lane champion, but players are finding that he has a lot to offer in this role after various buffs in recent patches. Like most assassins, his power lies in the early game, so it is important to try and capitalize on that. However, level six is where he really starts to show his strengths once he gains access to his ultimate.
By playing Nocturne in the mid lane, he has easy access with his ultimate to both top lane and bottom lane, meaning that he can easily move to help his allies if they are in a pinch. This kind of support can allow his laners to get enough kills early to help them into the late game while he can, hopefully, also have an impact in those later stages.
Kassadin

Kassadin is a champion that is fairly easy to learn but has a high ceiling, meaning that players who try him and like him can keep playing the same champion and still be improving with every game: also, he still provides his team with power at any skill level.
Kassadin is a very mobile champion with the help of his ultimate. He can easily move over walls to chase opponents and move in for an easy kill. Since Kassadin scales nearly infinitely, it is important to know that he is weak in the early game, so it is vital for players to stay safe until he hits his level six power spike and can start to contribute more in teamfights and skirmishes across the map.