I would like to ask the following questions: where is Prophet Muhammad (SAW) buried? And, is it forbidden to ask Allaah The Almighty for money?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

The Prophet, sallallaahu ‘alayhi wa sallam, was buried in the room of 'Aa'ishah and it was the place where he died. One of the characteristics of the prophets, may Allaah exalt their mention, is that they were buried where they died. Abu Bakr narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: "A prophet should not be removed from his place; he should be buried where he dies." So the Companions removed his bed and dug a place exactly in its place and buried him there. [Ibn Abu Shaybah] Additionally, Abu Bakr narrated that he heard something from the Prophet, sallallaahu ‘alayhi wa sallam, that he never forgot. He, sallallaahu ‘alayhi wa sallam, said: "Allaah did not take the soul of any of His prophets except in the place where they had wished to be buried.” [At-Tirmithi]

Regarding your second question, there is no harm for a Muslim to ask Allaah The Almighty to provide him with permissible wealth and this is something desirable in religion, as Allaah The Almighty ordered us to supplicate Him and promised us that He would answer our supplication. A person who supplicates to Allaah The Almighty is never disdained. The Prophet, sallallaahu ‘alayhi wa sallam, said: "Any Muslim who supplicates without entailing a sin or breaking ties with kinship (in his supplications) except that Allaah gives him one of these three things: Either his supplication is granted immediately in this world, or that it will be kept for him for the Hereafter, or that He repels from him an evil equivalent to that which he supplicated for." The Companions said, "In this case we will supplicate Allaah as much as we can." The Prophet, sallallaahu ‘alayhi wa sallam, replied: ''Allaah is more and ready to answer more than what you can ask." [Ahmad] Besides, the Prophet, sallallaahu ‘alayhi wa sallam, said: "A person should supplicate Allaah in every single matter of his, even in relation to his shoes if they are torn." [Ibn Hibbaan]

Allaah Knows best.