Images are Overstretched on Homepage

I have recently designed the blog https://www.matangakenya.com on the Pictorial WordPress theme. Unfortunately, all images in the home page are over stretched. I have tried to use regenerate thumbnails plug in, played with different figures on functions.php but nothing is changing.

Secondly, I am unable to remove the tags, categories, posted under … on single posts… i have checked on almost all files under editor, added a few codes but nothing is changing!

I would really appreciate some help!