Hello,

As your blog thumbnail images looking blurry in home page. Try to use the following size for thumbnail as 150*150 or also try with increasing the size of thumbnail: https://jmp.sh/3KrjNfg

Also after changing the Image Size as per your requirements from Setting >> Media run this plugin to resize all your existing images to the new size: https://wordpress.org/plugins/regenerate-thumbnails/

Best Regards.