If I had advice to give my younger self, I'd have to be very careful about the whole causality problem. At 45 I have two awesome kids aged 5 and 2. I have an amazing wife who multiplies both my happiness and ability to make a living. Both my wife and I were previously divorced. I wouldn't change anything that might prevent me from meeting her and helping to bring my kids into the world.
If I had perfect temporal guardrails that would ensure this family path, I'd tell my younger self that it works out pretty well in the long run, but huge mistakes were needed to forge me into who I am today. Also, buy Nvidia stock.
Well, there's an outside chance that eating dead people is unhealthy.