Knowing where to start is the hardest thing. FM has a C Major scale written down on his beginners guide. It has no sharps or flats so when you see written music with no sharps or flats at the beginning you know the scale is C major. (when you DO see any Sharps, you can easily identify what is the Key signature from the sharp note written furthest on the right, it is always on the note beow the KeySig eg. If it is on the top line, the F line, it is key sig G major. On the E line makes it a F major.
I learnt GMajor to start coz it only has an F sharp note, all the others are natural.
Now use FM fingering chart and it will show you, for each Key Sig which notes are in that scale and where to find them on the fingerboard. Hard part after that is to know if you hit the right notes. I used my violin tuner for that.
It's all down to memory really when learning each scale/Key Sig ( except the finger spacing is always the same.
Eg if doing G maj. Start on the Lowest G note. Finger spacing is always space space together space space space together. So 2 space,together, 3 space, together with your finger position. You will see this on FM fingering chart.
I hope this hasn't confused you even more…….
I'm sure FM will put me right and tell you a much easier way of learning scales lol

Ah! Sorry, in that case you can write in your own 2 octave scales by using my 2, together, 3, together, finger pattern. But I'm sure the 2 octave scales will be on the web somewhere.