Text output is the best first EUD to get working. Unlike the classic Display Text action you control colour and line breaks, and you can interpolate values.
DisplayText("\x13\x1F【 \x04안녕하세요 \x1F】");To show values alongside text, use f_eprintf. Braces are placeholders and the values follow in order.
f_eprintf("\x19{:n} \x1D|\x04 \x07레벨: \x04{}", CurrentPlayer, level);