How to retrieve page formatting

I don’t know what version of WP I have as I had someone install it for me maybe about a month or two ago. I was trying to change the url in the header of the page from http://www.gateway2wealth.com/blog/ to http://www.gateway2wealth.com and when I did this, I lost all the formatting for the page, cannot log in to correct anythind and can’t find where this came from. I don’t know how to fix this and hope that someone can point me in the right direction.