[twenty Eleven] how to add thumbnail post on the home page and blog page?

Hi
can anyone help me with this problem that i have at the moment. i am working with a client at the moment and they want 3 latest thumbnail blog post on the home page and the blog post on the blog page to be thumbnails to (like link 7 image on this page https://www.hongkiat.com/blog/40-most-wanted-wordpress-tricks-and-hacks/). I have tried everything and nothing seems to work.

this is the page that i want to add the 3 latest blogs post side by side in boxes https://www.mycampusride.com and this is where i want to have thumbnail blog post as mentioned above https://www.mycampusride.com/blog/

if anyone can help i would be so happy as i have tried everything and i dont know how to do this