Pretty generic, but, stop chasing after these thots. Use your 20s finish college, learn a trade, etc. I'm not saying don't date or whatever, but focus on improving in your career. The women ain't going anywhere.
Kind of relates to the first part, but live your life. Grinding is cool for temporary purposes, but don't make working 60+ hours a week a lifestyle.
Avoid fast food, alcohol, soda, sweets, etc. You ain't going to have that fast metabolism forever!
Make it a habit of regularly working out. It doesn't mean you have to be a gym rat, but at least 2-3 times a week.