Every key has 7 different positions: Lydian, Mixolydian, Aeolian, Locrian, Ionian, Dorian, and Phrygian.
When playing in the key of C Major, every one of these scales can be used, and be in this key. Practice playing each of these in different styles. I learned to play each in different ways which I will list on here as well, but here are the scales first:
1st Position (Lydian)
2nd Position (Mixolydian)
3rd Position (Aeolian)
4th Position (Locrian)
5th Position (Ionian)
6th Position (Dorian)
7th Position (Phrygian)
So those are the 8 positions. And just so no one gets confused or anything, I put these from the beginning to end on the fret board. However, if you want to be technical, the real order of the positions goes Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian. I just wanted everyone to be able to look at these and see where they all connect, hopefully its easier.
You should try and master each of these, one at a time, and before moving on to the next one, you should be able to know how to play each in from beginning to end, and end to beginning. Also, A good bit of practice with this is to play the scales like this, Ill use the Ionian Scale as an example.
I know that might look confusing, but if you start doing it on guitar, it gets to be pretty easy. Also, another good trick is to try this and always have your fingers stay on the note and just move the finger you need to to continue the scale. Like, for the Ionian scale, you would do 8-10-12 on the low E string, and then you would keep you middle and pinky fingers on the 10 and 12, and then just move your index finger onto the 8 on the A string, and then after that move your middle finger on the 10 on the A string, and still keep your pinky on the low E 12, then move your pinky on to the 12 on the A string, and continue like that up the scale, its not easy, but its very good for training your fingers.
Well thats just about it for this lesson, and just so you know, it took me about 2-3 months to get everything on here mastered, since my teacher only gave me one a week, and I would have to practice each of them with all these things, and then eventually memorize the names in order, then play them by the name of them, which he called out randomly, so don't get mad if its taking a long time, and seriously, don't try and rush it cuz you'll get it all confused and just end up hurting your guitar playing in the end.