Dell xps 15 9550 Charging

Hello, I've recently bought a dell xps 15 9550 and have two questions in regards to charging it.

The first is, Should i charge it out of the box before use, mine came with 96% charge so i didnt think i needed to.

Second is, what are the led indicators for the laptop being fully charged, i noticed the light on the changing cable is always white. Thanks in advance.