League of Legends: your first evening on the Rift

Ninety minutes, three matches against the computer, one champion. By the end you will know what a lane is and why the dragon matters.

Make the Riot account and install the client
The client installs Vanguard on Windows and asks for a restart. Do that before you sit down to play.
Play the tutorial to the end
It is short and it teaches the two things nobody explains later: recalling to base and buying items.
Choose a simple champion and a simple lane
Garen in the top lane or Annie in the middle lane are the classic first picks for good reason: few buttons, obvious jobs.
Three matches versus AI
Co-op vs AI at Intro or Beginner difficulty. Concentrate on last-hitting minions and not dying. Ignore the chat entirely.
Then one normal draft
If you feel ready, play one match against people. If you don't, play more bots; there is no clock on this.
Close the shop tab
The client will show you skins and events every time you open it. None of it matters this week.

Before you go

Lock your camera for the first evening if the map makes you dizzy; unlock it in the second week.
The little map in the corner tells you where everyone is; look at it every time you buy.
A death is a lesson, but two deaths in a row is a reason to play safer, not harder.
You do not need Riot Points to reach the highest rank in the game.

Read the full League of Legends chart entry for the bearings, the toll and who it suits.