a scale is made up of 7 musical notes and the 8th being the root note but an octive higher meaning a double in frequency to the first original note.
to find a scale you need to know the formuler to add to the notes
for a major scale you need to use they key of TTSTTTS. the t standing for tone up and the s for semi tone up.
for a minnor scale it changes to TSTTSTT.
a faster way to do this is to use the circle of fiths. this image below shows the circle of fiths this gives us how many sharpes and or plats are in the scale refering to the major scale.