How to resize images for posts on home page

Hi,
After uploading a photo to my WP media library then inserting it as a featured image for a post, I want to resize it or ideally crop it so what is left is what is visible.

But on my homepage the cropped image next to the post is a zoomed in part of the image.

Can anyone recommend a plug-in or steps to edit images for posts?

Additionally, the resize buttons (thumbnail, medium, large) are not visible in the edit attachment settings.

Any advice would be appreciated.

Thanks