Am i doing it right here?

[Hei]

A couple of days ago, i posted this thread asking people for help regarding figuring out the key for a song (and then i went MIA because i fell sick).

so i think i might be wrong the other day regarding what i posted the question, so i thought i'd say it more specific this time to try and clear things out. So it goes something like this....



i was trying to out the key of a song the other day, and let's assume i'd already gotten the key using single NOTES. Yes, notes, not chords. What am i doing here, is it correct? Using notes instead of chords. i simply played the low E string and find my way through what were the some of the notes present and somehow one way or another i got it. I also figured out of the riff of the song again using single notes, not chords. Does it mean the same thing? Pardon my stupidity if this is a simple question lol.

Next, since i've already gotten the key (let's assume it is in the key of C major), will i be able to figure out the solo/improvise over over the key of C using a scale.. say... C major Pentatonic. Musically speaking, will i be correct?

 

[Scarified]

If your correct and it is in the key of C major you may solo over with the notes of the C major scale, C D E F G A B. Figure out all the notes in the key and play them in various positions on the fingerboard.
For example an A minor pentatonic, start on the root note on the 6th string and scale up and down the 5th fretted position and when you've got the hang of it move on to a higher position and you can start to combine different positions adding more "colour" to your playing.
Just m 2 cents. Hope I helped