Reduce the space between posts and previous next posts

Dear Members,

I have created this website and there is gap between the posts on home page. I would like to remove that gap. Please support me.

https://www.sheepandgoatbreeding.com

And also I want to have previous option on top/bottom left and next option top/bottom right of the post.

https://www.sheepandgoatbreeding.com/goats/

Thanks in advance.

Regards
Abdul