a face or facade that you put on when you want others to think you are happy and that your life is perfect, when in reality, you aren't.
Sonny describes a Copa as prize or award and that a copaface would be the face you have when all eyes are on you and you have to look like you are perfect and that your life is happy.

A spicy way to insult your degenerate friends.

“Sussy” and “sus” are words used in the videogame Among Us to describe someone shifty or suspicious.

Baka roughly translates to idiot in Japanese and is a common phrase expressed by tsundere characters in anime/manga.

Originally coined to insult A2B2 user TSUNDEREBOY, the meme spread from discord to TikTok and propagated in the following days.

"Copaface originally referred to people who were attending the Copa Cabana night club in New York. The expression was.

"Have your gal put on her Copaface and take her to the Copa for the evening".

It dates back to the 1930s and means a happy face."

...according to walt631 - Yahoo! Answers.