Blog Designer, how to put my blog in the center?

Hello,

I use Blog Designer for my website but when i make a post i noticed that the blog post itself (not the text)is not aligned to the center and is to the left of the screen.
How can i change this?
Also the pagination on my home page (above the blog post grid) is not centered aswell (https://www.filmzone.nl/).
I hope someone can help me with this.

The page I need help with: [log in to see the link]