Here are all the key signatures:
0 # or b = Key of C major / A minor
1# = Key of G / E minor
2# = Key of D / B minor
3# = Key of A / F# minor
4# = Key of E / C# minor
5# = Key of B / G# minor
6# = Key of F# / D# minor
7# = Key of C# / A# minor
0 # or b = Key of C / A minor
1b = Key of F / D minor
2b = Key of Bb / G minor
3b = Key of Eb / C minor
4b = Key of Ab / F minor
5b = Key of Db / Bb minor
6b = Key of Gb / Eb minor
7b = Key of Cb / Ab minor
Anytime you are figuring out a scale pick a starting note then list all the notes of the alphabet used on the piano starting with that note. Example let's pick Gb. First write out the letters from G to G:
G, A, B, C, D, E, F, G
Next, put a flat next to G to indicate the key Gb:
Gb
Next, go through the W W H W W W H formula to find the other notes:
Gb, whole step, Ab, whole step, Bb, half step, Cb, whole step, Db, whole step, Eb, whole step, F, half step, Gb.
Notice that once u get to Bb, the next note can't be B anymore cuz B is already flat. Since the next note is C something, it must be Cb. Does this make things clearer for u?