Commitment day has come and gone. Your student has declared and you know where he/she will go in the Fall. It's an exciting time!
But that tuition bill come soon enough. Unless your student got a full ride (very uncommon), you - the parent - will have to write a check. And using retirement accounts is a common strategy for parents.
If you do so, don't make these mistakes!
https://www.irahelp.com/slottreport/tapping-ira-pay-education-expenses