The Major Scale is the building block for music. It is basically a 7 note step. It is made up of whole steps and half steps. Any time you skip a fret and play the next note, it is a whole step, if you play the next fret, it is called a "half step."
The note you start on is the key of the scale. If you follow the step pattern of whole step, whole step, half step, whole step, whole step, whole step, half step.
Try playing the scale on one guitar string only before moving on to other ways. I found a cool video that explains what I have written here:
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