add captions to photos

I have photos on my WP website in the content area (not sidebar and not the header). I have attempted several times to add a caption and it does not work.
First I tried adding a caption in the media library for an image and clicked “update media”. No change in the image on the webpage.
Then I tried with a new image and filled in the box for the caption again. Added it to the page, and there was no caption.
Either way I am not able to add a caption to images in the content area of my website.
Any help for a non-techie is appreciated.