Is this a good game to go into with zero guitar skills? Or should I have at least a basic understanding before I play the game?
Only using Rocksmith might not be the best way to do it for most people. Combine it with either lessons or justinguitar.com and you will see some progress very fast.
I personally have used Rocksmith for the most part when learning guitar and then a bit of youtube and just learning songs from tabs. That has worked great for me.
I got the first Rocksmith just over 2 years ago now and in total I have 760 hours in both games combined (maybe more like 700 if we get rid of afk time and shit as well). The game keeps me motivated to keep picking up the guitar and the enormous library of custom songs on PC is great. While there is a lot of poorly made ones, there's still plenty of good stuff to keep you busy.
Can't recommend this game enough if you want to learn guitar.