How Do Sleep, Confusion, Paralysis, and Poison Work?
Some attacks cause the Defending Pokémon to be Asleep, Confused, Paralyzed, or Poisoned. These things don't happen to a Benched Pokémon, only to an Active Pokémon - in fact, if a Pokémon goes to the Bench, these things are removed from it. And evolving a Pokémon also means it's no longer Asleep, Confused, Paralyzed, or Poisoned.

Asleep

If a Pokémon is Asleep, it can't attack or retreat. Turn the Pokémon sideways to show it is Asleep. After each player's turn, flip a coin. On a heads, the Pokémon wakes up (turn the card back right-side up), but on a tails it's still Asleep, and you'll have to wait until after the next turn to try to wake it up again.

Confused

If a Pokémon is Confused, you have to flip a coin whenever you try to attack with it or whenever you try to make it retreat. Turn a Confused Pokémon with its head pointed toward you to show it's Confused.

When you try to make a Confused Pokémon retreat, you first have to pay the Retreat Cost by discarding Energy cards. Then flip a coin. On heads, you retreat the Pokémon as normal. On tails, the retreat fails, and that Pokémon can't try to retreat again that turn.

When you attack with a Confused Pokémon, you flip a coin. On heads, the attack works normally, but on tails your Pokémon attacks itself with an attack that does 20 damage. (If your Pokémon has a Weakness or Resistance to its own type, or if there's some other effect that would alter the attack, apply these things as usual.)

On tails, the Active Pokémon does 20 damage to itself even if its attack normally doesn't do damage (like Squirtle's Withdraw attack).


Paralyzed

If a Pokémon is Paralyzed, it can't attack or retreat. Turn the Pokémon sideways to show it's Paralyzed. If an Active Pokémon is Paralyzed, it recovers after its player's next turn. Turn the card right-side up again.

What this means is that if your Pokémon gets Paralyzed, it will be out of action on your next turn, and then it will be okay again.

Poisoned

If a Pokémon is Poisoned, place a "poison marker" on it to show that it's Poisoned.

As long as it's still Poisoned, the Pokémon takes 10 damage after each player's turn, ignoring Weakness and Resistance. If an attack would Poison a Pokémon that's already Poisoned, it doesn't get doubly Poisoned; instead, the new Poison condition replaces the old one.

Make sure whatever you use for a poison marker looks different from a damage counter.