These are all excellent questions in their own right. Please feel free to ask for additional clarification on any of them (one at a time, of course). What I will do in this reply is give you a few statements for each of them — an overview, if you will.
Studies: Life is short. It may not seem like it to you yet because you’re still young. But it’s short and it can end with little or no notice. So, find something you love to do and do it. As Leonard Cohen (famous Canadian poet) put it: “I don’t want to work for pay, but I want to be paid for my work”. If you can possibly earn a living while doing something you love, it’s like getting an extra life. Seriously: you’re asleep 1/3 of the time and at work 1/3 of the time and your time is your own the other 1/3 of the time. So if you love your work then the last two merge into a satisfying and healthy lifestyle.
Money: In short, the rule is: never get on the wrong side of compound interest. In other words, if you want to buy something, save up some money and then buy it. If you wave cash in front of the vendor, they’ll usually give you a few dollars off. In addition, you will receive interest (aka free money) on that money you’re saving up. Many times, those who buy things on credit end up paying double or more. Here’s an appropriate Albert Einstein “quote” (which he never actually said, but it’s pretty accurate, so many people wish he had): “The most powerful force in the universe is compound interest”.
Fashion: Always go classic. When you get married, wear a nice suit — not the baby-blue velour that’s in fashion for a year or two (believe me, you’ll be embarrassed the rest of your life when your wedding pictures are viewed!). What seems appropriate and new (jump suits, very short shorts, ruffled shirts, etcetera) don’t last. Probably the best thing to do is look over the past 15 years or so and see what’s been common clothing throughout that time. Same thing goes for haircuts, jewelry, etc. If I had to make a simple rule it would be: don’t try to stick out; don’t be a peacock.
Well-Being: This is of paramount importance. Right now, you’re young. You can eat fatty, crappy food and it won’t appear to make a difference. But I think it does — I think it’s filling up spaces inside your body, and when those tiny empty spaces are all full you start getting fat. So: eat right and exercise by doing activities you enjoy (go on a walk instead of being on a treadmill). All things in moderation (including alcohol, of course). Avoid drugs and smoking like the plague; my feeling on drugs is that some of the modern synthetic ones are particularly dangerous as they directly kill brain cells and/or do genetic damage. Finally, learn to cook! It’s fun, you’ll save a LOT of money (you can eat filet mignon for the price of a McDonald’s meal – did you know that?) you’ll eat better (restaurants like fatty food because fat tastes good (that’s a genetic thing with humans because fat is high energy and food wasn’t always available) and fat is cheap). Oh, and women love a man that can cook.
Girls: are interesting. Avoid them until you’re about 28 or so. There are good reasons for this and I’ve covered it in depth in previous entries. It boils down to this: males mature (mentally) fairly slowly and you won’t be fully hatched until about age 28. Without getting tied down, you will be able to concentrate on your studies, well-being and money; these are all good things to have concentrated on because by age 28 you’ll have a good career, will be physically in top condition and will have cash. Cash is the ultimate aphrodisiac but when you look good and have a great career on top of that, you will have your pick of women. One more thing: if you want to know what they’ll be like in 20 or 25 years, be sure to meet their mother. I’m probably going to get roasted by women for this answer…
Anyway, I hope this helps. If there are things you would like more information on, JustAskOldGuy.