I have a child who started school this year and also began learning violin this year.
I personally have learnt guitar for over 20 years and can easily sight-read music.
Prior to my son starting lessons I spent a few weeks trying to figure out how to play. I had access to many beginner lessons and color coded or numbered sheet music but this didn't help. I also tried watching a few videos on Youtube.
My opinion is having a background in guitar, reading and understanding the music is no problem, but it may make taking up the violin slightly harder because there are little things which are slightly different and the way the frets are structured on the guitar and how you are used to placing your fingers feels different.
You are going to make leaps and bounds by taking some lessons. My son went to an introductory class for about 10 lessons and this made things a heck of a lot clearer for me (I sat and watched during his lessons).
My suggestion is taking an intro course and you can take it from there. But, you will likely need to take other courses later to pick up further techniques.