If you aren’t using a checkbook and are using banking apps, make sure you are keeping tabs on what is in your accounts. This is also where budgeting matters.
Budgeting is a personal finance basic all should master at first. Spend some time on your bills, your living expenses, what you are spending money on, your savings, etc
No matter your feelings towards the credit scoring system, building good credit is so essential. It can truly affect your ability to rent an apartment, buy a house, get a car, etc.<
Start with the very basics of investing, how it works, what a 401k or IRA is, etc. Then move on to managing your investment portfolio and what the maintenance looks like on that.