Some of us spend within our means with credit cards, collect our perks, and have done so for longer than you’ve been alive.
This doesn’t require a high IQ. Make a budget or use one of the many tools that help you with that. Leave slack for emergencies and build up 3-6 months of savings. After that, invest what you don’t spend.
Live in the budget. Don’t ever spend more in one area without taking that away from something else.
Money isn’t mysterious. It requires nothing more than being able to add and subtract. Credit is good.