Buttons on launch/home page

Site URL: http://swan-crow-9fwz.squarespace.com

Question from a new user:

I have created a launch (home) page and wish to have 2 buttons on it, one linking to business a and one linking to business b.

I seem to only be able to add a button to the header, I would prefer to be able to place it on the picture I have inserted.

I would like to add a second button for the second business but I seem to only be able to overwrite the first button.

Anyone got any ideas?

Thank you.