A: Lets give some sample names to the players, and then we’ll list the steps with numbers.

So, let’s say that Anice, Bex, and Clarence are playing Around the World Fluxx. All of them have Keepers in play (on the table in front of them).

On her turn, Anice plays “I’m Lost.” The card tells her what to do (card text in bold).

1) Choose any player who has at least one Keeper.
Anice chooses Bex, who has The Eiffel Tower in play.

That player becomes lost!
Bex is now considered “lost.”

2) The lost player (Bex) must now choose one of their Keepers and discard it.
Bex chooses to discard The Eiffel Tower.

3) They (the lost player, Bex) will now choose another player to help them find their way.
Bex chooses Clarence to be their helper.

4) The helper (Clarence) must then choose a Keeper they have in play and transfer it to the lost player (Bex).
Clarence has some Keepers in play, and chooses to transfer Machu Picchu to Bex. Bex now has Machu Picchu in play.

5) As a guide fee, the helper (Clarence) then draws 1 card.
Clarence draws one card and puts it in his hand.

6) is a note: If no one can help the lost player (if no one has any Keepers in play that they can transfer to Bex) then no one gets the fee (the extra card in their hand).

Further notes:

Note that step 1 says “choose any player” (emphasis added). This means that Anice is allowed to choose herself to be lost, in which case she follows the directions for the lost player.

However, in step 2, the lost player must “choose another player” (emphasis added) to help them find their way. This means that Bex could not choose themselves to be their own helper – but they could have chosen Anise as their helper, and Anise would have had to give Bex one of her Keepers, and get the extra card in her hand.