I'm looking the allstate music (as my class is required to pass it off) the piece is in concert c minor. I play flute and on my f(which is already sharp) there is a natural sign and then another sharp sign. I haven't seen this before so I'm hoping someone will know
The natural is there as a cautionary - in the previous bar there may well have been an accidental for that same F note (guess it's treble clef), most likely an Fx, so it's just saying 'this F is an F♯ now'. Followed by an Fx (F double sharp, same pitch as G).
It's just a reminder - you play that F as an F♯.
It's the old notation for a normal sharp when double-sharps (as on the following note) are in the vicinity. Possibly the F in the preceding bar (which you have just avoided showing us!) was a double-sharp? In that case, the 'natural-sharp' notation, though not strictly necessary, could be a useful cautionary.
The more modern style is just to write the sharp, even after a double-sharp in the same bar. The natural is not used. But you'll find plenty of older music that does it this way. We could compare it with the old style of cancelling a key signature with naturals before writing the new one. Now we just write the new one - naturals are only needed when moving into the open key with no sharps or flats!
Gould (2011) refers to 'traditional' and 'contemporary' practice. "When a double flat is cancelled by a single flat, and a double sharp by a single sharp, the traditional practice of placing a natural sign before these is redundant, since a single flat or sharp sign cannot mean anything else." Garner Read (1969) concurs. "To cancel a double sharp, one now merely writes a single sharp-sign."
Are you SURE this piece is in C minor? I'd expect a key signature of at least three sharps in this context! Perhaps C♯ minor?