I never took any music lesson. I just learned from experience most of my life- I'm more of a visual learner myself so I'm going to explain these things that best that I can and hopefully you would find them useful.

what's a vibrato?
a vibrato is the slight fluctuation in pitch that helps long notes sound fuller and less stagnant. It is achieved by rapidly pushing the string up and down.

what's a harmonic?
Okay, how do I go about explaining this one... okay, here it goes: a string's length and tension determines the frequency at which it vibrates. This pitch is called the fundamental or the frequency generated by the full length of a string. However, strings also vibrate in fractions of their length. This is what you call harmonics. Harmonics are multiples of the fundamental frequency that gives a string its rich, complex sound called timbre. If you pick a string exactly at its center (let's say the 12th fret of an open string) you will hear mostly the fundamental. The sound is bassy and round. As you pick closer to the bridge, you will hear more of the harmonics and the sound is brighter. I know it's a bit confusing but it's not that hard once you try to do it in the guitar. Just remember to lightly rest your fingers and don't press the strings.

is there a wrong way to palm mute?
can u elaborate on this one? how do you do your palm mute?