Hola, You are right, "No sé qué ponerme." means "I don't know what to wear.", or it literally means "I don't know what to put on." You can also say "No sé cómo vestirme." (I don't know how to dress up.), however the first option sounds a bit more common. And the explanation you gave is also correct. qué + inf = what to do cómo + inf = how to do Also, if you want to say "Tell me what to do.", it would be "Dime qué hacer." BUT if you want to say "Tell me what to wear.", instead of saying "Dime qué ponerme" you should say "Dime qué me pongo." And back to the original sentence, although the natural version is "No sé qué ponerme.", grammatically it is also correct to say "No sé qué me pongo." beauties of the languages, right? :)

I´m learning spanish myself, but I´ll give it a try: I believe it works like in English, but with the exception of the infinitive particle "to". Since you don´t have an infinitive particle in Spanish, even though in some cases the preposition "a" is used (comenzar a estudiar), PONERSE = "to wear/to put on". Following that logic, the structure is actually the same: "Qué ponerme" = "What ´to wear´". In short: Yes, you are right. PS I´m obviously disregarding the fact that ponerse is a reflexive verb when I say the structure is the same, for the sake of simplicity.