That is not true. If you aren’t seeking need based aid you check ‘not applying for financial aid’ on the common app and that’s it. No financial aid forms needed. At some colleges it’s an advantage to not be applying for need based aid
If you do want to take out the federal direct student loans you would need to file FAFSA (but not CSS.) That loan is $5.5k for the first year and goes up a bit after that.
Some (not many) colleges require FAFSA for merit aid.
You might make sure you don’t qualify for need based aid by running some of the net price calculators for schools you are applying to. Put in all the financial info you have, mom, dad and yours to get accurate results, at schools that require CSS.