Removing right sidebar (blog)

Good day to everyone.
I am building a basic static site. All the pages are fine.
I recently added a contact form, but the “blog page” shows in the right sidebar.

I would prefer to eventually have a separate page for the blog. How can I remove the sidebar so that the contact us page only contains the form?

I also see the four footer widgets at the bottom. I use to of them, but the other two are just sitting there empty. How do I remove them?

Please have a look at the screenshot here:

Your input would be greatly appreciated.
Renier