2013 Prius C One 76k mi creaky sounds

My Prius is making creaky sounds sometimes when going over bumps or dips or inclines etc, sounds like I need to WD40 some spots. Is there something I should check first? I've had all my oil changes but missed one or two milestone maintenances a long the way, just checked engine filter still clean changed cabin and my oil, my pink fluid coolant I guess is directly on Low, should I do something about that as well? Thanks