You could say, "Nani wo shiteru no?" It is also possible to say: "Nani shiteru nan desu ka?"
Nani shiteru no? 何してるの?
Japanese pronunciation is actually very easy. Japanese words consist of two letter syllables with four exceptions - shi, chi and the letter n by itself, and vowels by themselves. Unlike English they are always pronounced the same. Nani would be pronounced nah nee. In the case of shiteru, in the shi syllable the i is barely pronounced and the r is rolled with the tongue against the back of the top teeth. So it is most like sh te ru. na ni wo shi te ru
nihon de nani o shiteru n da I think. But I know that nihon is Japan, and nani o shiteru n da means what are you doing x 今日 (kyou) is the word for today, adding the previous makes "what are you doing today?" to be 今日に何をしているの? (kyou ni nani wo shiteiru no?).
"What are you doing?"
The answer is Nani or 何"nani?" or "nan desu ka?"
Nani generally means why or what
何 - Nani
"I love you" in Japanese is pronounced as "愛してる (ai shiteru)" or "大好きだよ (daisuki da yo)."
"Doyoubi ni nani wo shimasu ka?" (pronounced: doh-yoh-bee nee nonny oh shee-moss kah?)
Nani o shimasuka.
何 (nani)