Did you know that we use special nouns when speaking about nationalities? The only exception in the adjective “Russian”, also meaning a nationality.
Он француз. He is French (Nationality).
Это французское блюдо. It is a French dish (Adjective).
Она испанка. She is Spanish (Nationality).
Это испанский танец. It is a Spanish dance (Adjective).
Я русская. I am Russian.
Это русская песня. It is a Russian song.