Anchor links not working properly.

This is the website.

https://manattdigitalmedia.cloudapp.net

The website has anchor links and is composed of two pages and a lot of posts. I have one primary menu. I registered another menu named “blog”. How would I go about writing a php in the function to use “main menu” for home and “blog” menu for everything else on the website? Currently if i go to the BLOG page, my menu’s don’t work.

Any help would be greatly appreciated.