"DON’T BUY SHIT ON CREDIT, REMEMBER WHAT HAPPENED TO AMERICA? CASH ONLY, FUCKERS. CAN’T AFFORD IT? DON’T FUCKING BUY IT!"
This is almost right. Yes, never buy something you can't afford. However, your credit rating makes or breaks you in this world. Get a credit card, make a point of using it at least once every month, never keep it at more than 20% capacity, and ALWAYS pay it off (never carry a balance).
Credit ratings take YEARS to build. Start early.