Rasp pi open cv with pi camera mod 3

hi trying to get some help,just learning and not young.should have started when my brain was working.have a raspberry pi 4 with pi camera module 3 have pi 4 working fine have camera working fine can see image.have servo hat hoping to control servo with camera.installed open cv and trying to get some kind of image or video to show up.have tried several scripts from on line to no avail.i know cv is installed because it gives me the version.i wondered if an expert could give me some next steps to get the open cv to work mabee a simple script just to see the camera.picture,video,etc.thank you in advance for any help