Editing Shop Option

Hi, can anyone support on these queries below:

1)In the shop page I am automatically seeing 4 products vertically in one line, I just one to reduce that number to 3 or 2 products. How do I change that?

2) In the product image there is an option for read more where it takes to single page of that product. I want to remove the read more option and put another link of my own which will take to another website.

3)How I make the images clickable so it goes to another website page, a link to another page.
Thank you.