Looks like you dont have the modal loaded. If you only need it on the home page edit the home page and go to the bottom of the setting below the content editor. You will see easy modal settings and will be able to choose which modals you want to load.
Once you enable a modal any links for it should then work.
I installed EasyModal lite, I added a new modal, I set to be appear on every page. Nothing happened. Where example link/button/image codes should be copied? Is it possible to display button that opens modal automatically on every page? The other problem is that I can’t see the created modal at the bottom of page editor. The window is empty.