What does leveling up do in league?
Leveling up allows them access to new abilities or higher ranks of existing abilities. Many base stats and some items and runes scale with champion's level. Experience isn't gained over time, it has to be earned through different ways.
Does level matter in League of Legends?
It really depends and it's something you need to be aware of. Different champs spike at different times and for different reasons. For example, you're low, you're ganking a Garen who's low at level 5. If he hits 6 during your gank, you're probably gonna get executed.
Is LOL skill based MatchMaking?
The system estimates how good a player is based on whom the player beats and to whom the player loses. It tries to make matches where it thinks a player has a 50/50 chance of winning. ... As much as possible, the game tries to create matches that are a coin flip between players who are about the same skill.