These are some major bits of advice I wish I had when I was a white belt.
Focusing too much on winning in the beginning can create a lot of stress and frustration because you will be losing a lot, shifting to a focus of learning makes every class a success. Learning to see jiu jitsu as multiple positions rather than looking for over arching principle is another major perspective change that gave me a lot more clarity in my development. Lastly specifc training and video study were the big secrets to my long term success and development in the sport.