I echo the person who said to go to a salon, because this is a highlighting kit, and it is very easy to make mistakes. My friend used this kit, and the results didn't look professional at all.
I color my hair myself because I have a single color, and it is hard to mess it up. My hair also grows very fast. I used to have highlighted hair, but it was too hard to maintain, so I gave it up. My daughter also gave up the highlights, and she went back to her natural color which is a beautiful auburn.
If you don't have to color grey, I would keep my natural color. Most people have natural colors which suit them very well. Your hair looks very pretty.