Some challenges have hints that you can unlock. Some hints are free, some hints cost points to unlock.
If you unlock hints that cost points, those points will be deducted immediately.
To unlock hints, click on the question mark icon on the left hand side of the challenge interface. If the challenge has more than 1 hint, you can unlock them in any order.
Hints may have a preview to tell you the contents of the hint so you can decide if it's worth it to unlock them or not.
Hints do not impact your performance or ranking in any way other than solely the point deduction.