Elon's first piece of advice was to “Do things that are useful to your fellow beings, to the world. It's hard to be useful to the world, very hard”. In other words, do something beyond serving yourself, which he has exemplified in his work.
Secondly, “Try to have a positive net contribution to society. That's something to aim for”. This follows the same logic – try to give back something positive to society and everyone will be better for it, including you.
Thirdly, “A lot of the time, the people you want as leaders are the people who don't want to be leaders. Forcing yourself to do anything or be anyone you do not always end up in disappointment. Play to your strengths, and you'll succeed.”
Fourth, “I would encourage people to read a lot of books. Try to ingest as much information as you can and develop good general knowledge, so you at least have a rough lay of the land of the knowledge landscape.”