1. Don’t carry credit card debt. Save money if you can. Get a handle on basic finances

Credit cards are this weird thing. If you need them, you shouldn’t use them (if you can help it). If you make plenty of money and don’t need them, they are a very useful financial tool. I have paid interest on one of my credit cards once in the past 3 years, and it was only to have extra available funds for buying a house. But I have accrued well over 100k airline miles and several hundred (far more than the interest I paid) in cash back. I use credit cards exclusively for everything but my mortgage, and have them set to automatically pay the statement balance prior to the due date. If you aren’t extremely confident you can do that, you should avoid credit cards.

I definitely ran afoul of credit cards in my youth, so the banks have gotten their pound of flesh from me.