Creaking Noise When Going Over Bumps

In my experience, creaking noises are usually caused by a handful of things: worn bushings, worn ball joints, worn strut mount or components, or worn sway bar components. Basically, anything that pivots or moves can be a culprit.

Your Civic uses struts in the front, so it has fewer moving parts than some other vehicles with control arms.

You will need to get your hands dirty to know for sure and diagnose further. Jack up the vehicle. Any obvious visual wear? Does the sway bar move if you grab it and try to move it? Are the ball joint boots or sway bar link boots ripped?

Whether it's safe to drive, you can determine if it's unsafe by seeing if there's any play or movement in the suspension parts. You can grab the wheel (with the vehicle jacked up) and try to move it back and forth, top and bottom and see if anything gives. If any of the boots are torn, they are on borrowed time.