How do change the size of Blog Photos so they are smaller?

Store Design
1

https://carunyc.com/blogs/news

  1. We are looking to have smaller photos on our blog page

  2. We are looking to have a tile styled homepage

  3. We are looking to have 4 blog types/categories so you can click into them and see only those types of blogs.

I’ve tried adding code but I must have something overrides it? Is that possible?

Thank you!