Bear with me, I am a born-again newby, I am getting back into archery after being out for over 25 years.

I just bought a vision, and am attempting to tune it. Everything I see says that the brace height should be 7-7 3/4

the brace height is 6 5/8. did this come with the right string? and how would I verify that? it seems to me that it is way off.

2nd question is there a prefered starting point on this bow for the nock point?