
The C scale in first position is very important. These 17 tones can provide a basis learning to read music. They are all of the natural tones in first position.

The G scale can be viewed as the C scale with the F's moved to F-sharps.

The D scale can be viewed as the C scale with the F's and C's moved to F-sharps and C-sharps. Or the G scale with a C-sharp.

The A scale can be viewed as the C scale with the F's, C's, and G's moved to F-sharps, C-sharps, and G-sharps. Or the D scale with a G-sharp.

The E scale can be viewed as the C scale with the F's, C's, G's, and D's moved to F-sharps, C-sharps, G-sharps, and D-sharps. Or the A scale with a D-sharp.
In addition to the CAGED chord system, there are also CAGED Scale Forms (5 of 7 shown in this lesson). Each of these is an 'open position' [whatever this means] or 'open string' scale (a scale at the nut with open strings). Some of these scales are identical to the patterns we find in the 7 Major scales system, and some are slightly modified to utilize the open strings where possible. Some shifting is used where appropriate.
As we build our scale knowledge (to ultimately transcend patterns), we determine which fingerings work best for the type of melodic phrasing we are creating.
With all of these beginner guitar scales, we start with the root, play to roughly the highest tone in the position, then play to the lowest tone, and back up to the root, where applicable. We can also just play lowest to highest tone for the root [octave].
Take your time. As you build preparedness (the leave) into your scale playing, you'll find that chording and other techniques are quicker to process.