This is the 63rd most frequent Catalan word.
poder
"To be able to" or "can."
The word 'poder' is used here as a noun, meaning 'power', referring to the authority or control the king holds.
El rei té molt de poder sobre el seu regne.
The king has a lot of power over his kingdom.
The word 'pogués' is the first-person singular imperfect subjunctive form of 'poder', used here to express a hypothetical or unreal conditional situation, imagining the possibility of flying.
Si pogués volar, visitaria el món sencer.
If I could fly, I would visit the entire world.
The word 'puc' is the first-person singular present indicative form of 'poder', and is used here to express the ability to perform an action, in this case, going to the party.