This website is great at walking you through building a scale. Figure out the scale you need to build, Do it on your own, then CLICK THROUGH TO DOUBLE CHECK.
1.) Check the Clef (Treble/Bass)
2.) Get your starting note
3.) draw out the 8 notes alternating lines and spaces
4.) use the wwhwwwh pattern to add sharps and flats
https://www.8notes.com/school/theory/the_major_scale.asp