As far as money goes, some cousin or old chum is going to give you a call and want to sell you some life insureance. Tell him to fuck off. DO NOT buy a stupid fucking whole life insurance contract. Some term will do AFTER you have a wife and kids. And start putting some money away for retirement as soon as you can/
Even with that just make those mistakes and live with them. Even when you are 80 there are still things you are not going to know. If I'm 100 what would I tell my 80 year old self? You will never know it all.
Knowing this when you are young could be helpful: Being at peace, is the meaning of life.
Of course you will spend the rest of you life defining peace.