I just love rock music do you have a personal favorite band?
I like rock music too. Rock music originated in the 1950s. My favorite is Metallica. 
What instruments are predominant in rock music? 
Rock music is centered on the electric guitar. 
Are the vocals usually a focal point?
Nope.  Rock music drew upon other genres.  Like blues, folk and jazz. 
When was the first rock music recorded?
I have no idea. But it is generally accept that African-American genre of music helped form it. 
Do you have a personal favorite instrument?
My personal favorite is the viola. That is stringed instrument similar to the violin.