Catagories andThumbnails PLEASE HELP!

Hey,

I was wondering if anyone on here would be able to help me out with this. I am looking to turn the home page blog posts into thumbnails with a small excerpt. Like 4 – 5 of them in a row and I am trying to get them divided for multiple categories. Please see what I have so far so you can further understand

https://ddh.internetisdead.ca/

Example layout

* CATEGORY TITLE 1 *
– POST 1 – POST 2 – POST 3 – POST 4

* CATEGORY TITLE 2 *
– POST 1 – POST 2 – POST 3 – POST 4

Thanks so much