How do I create a solo that emulates the vocal line if I dont know the notes or cant get a tab of what someones singing?

Is transcribing simply taking the notes off one instrument and playing it on another. As I just transcribed an Elton John song and it is not even close to recognisable.
You need to figure it out, either by buying sheet music or by ear. Some of the guitar pro tabs on this site have vocal melodies. Learn what key its in, how it relates to the chord. The way I like to see it,

C chord = C E G

The melody will most likely start on one of those notes.

Transcribing means to write a piece onto stave music by ear. It's what I spend most of my time doing with my pieces and other peoples, its really hard at first but it gets gradually easier. Learn intervals and their uses and then look up demonofthenights blogs on melody.

www.musictheory.net this has an interval ear trainer and some other stuff.

Hope this helps .
sing the vocal melody, then play what you sing
might take a while depending on how trained your ear is,
but do it with every song you can think of and you'll become faster and faster
it really just takes practice. generally the vocal melody will more or less follow the chord progression, it tends to focus on the notes of whatever chord is being played.
Hah when I'm practicing for about 4-6 hours on some days, if a vocal melody has been stuck in my head, like some Sting or Moody Blues thing, I'll transcribe it just for the ear training it provides. Trust your ears, and you will find the notes. With some legato, your guitar will sing just as well as Sting does.
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