I would advise myself to always be prepared, physically, emotionally, intellectually and spiritually, for whatever might happen. Remember that anything can happen to anyone at any time. And when that "anything" pleasant or unpleasant does occur, remember that it is the Hukam of Vaheguru. There is nothing to worry about.
In my affairs with others, be kind. Sure some people will mistake kindness and gentleness for weakness and take advantage. That's their problem. Looking back on my life, I most regret the times I have been unnecessarily unkind.
And to live according to one of my Dad's favourite lines, "Always look up. Sure you might stumble and fall once in a while, but how else can you see the stars?"