Can a Pokémon attack more than once per turn?
As stated in the official Pokémon TCG rulebook:


  Once you attack, your turn is over (…)!


Pokémon TCG is a round-based game (just like Nintendo games) so you only get one attack as the last step of your turn. Even though you have enough energy to use an attack twice or to use two different attacks, you still need to choose only one attack and use it only once.