When choosing a career, choose one that makes good money over one that you think you'll enjoy, because in order to just live comfortably you need to make A LOT of money these days. By comfortably I mean being able to afford a home, save for retirement, own or lease a good car (usually more than one), raise children, put them through college, afford vacations, etc.... This is why you most families need two incomes (husband's and wife's) just to stay above the poverty level.
Don't give your heart to anyone online. I'm not talking about catfishing (people pretending). I'm talking about how people, real people often have more sides to them than you think and you shouldn't be surprised when you uncover a side of them that completely changes how you feel about them. I've learned that the only people I really knew and loved were the friends I had growing up (before the internet existed).
Also, life is really an endurance sport. Keep yourself physically fit and it will keep you mentally fit as well. Especially when you have to face life's hurdles. Exercise is also the best preventative medicine around.