There is one rule to personal finance that will always be true if you want to save for the future: spend less than you earn. As long as you do, debt will not be an issue. Now there are things that are ok to go into debt for, like school (and having school loans) or a car (to transport you to the job where you'll acquire money to pay off a loan) but beyond those core categories there is no reason to go bankrupt for some new product you already have that works fine, or other non-urgent purchases.
Some people say the present is all we have, so don't think about tomorrow. Like it or not tomorrow will come, and there will be a time when getting a job may not even be possible (yay disabilities and agism) and you will be thankful to have a reserve of emergency funds to tap into. I know I was when I got into a car accident two months ago and paid the full deductible with cash. There is a peace of mind knowing you have a cushion before you fall on the metaphorical concrete and break the bank.
Spend less than you earn and build an emergency fund. Those two tasks will make a world of a difference, lifting off the weight debt can place on your life.
Spend less than you earn by hiding the money by putting it somewhere else – a piggybank or savings account will do.