Like everyone's been saying, learn to take care of yourself. Cook and eat well and exercise and sleep. But also just fuck around a lot. Say yes to things. Try something new every time you can, even if it's just a dish you've never had. Meet people and talk to them and have fun with them. It's harder to meet people as you get older.

Travel if you can, but you don't need to be a jet setter to have new experiences. Find trails and museums and go listen to live music. Try creating things, you don't have to be good at it or keep doing it, just doing it is the point.

Aging comes with a certain amount of solidity, in your energy and mind and responsibilities. It's amazing and it's not something to fear, but it does mean you can't just fuck around as much. And if you're going to be a person for the rest of your life it might as well be a person you like.