Lost my website

Help please!!!

I am working on a site for a client, that I had not originally created and I am very new to wordpress.

Saturday I had changed mine (admin) and another users password, as insisted.
I also changed the e-mail address of the original admin (other designer) to mine, since
I was taking over the maintenance.

Today we find out that our website, trainatjoes.com is no longer appearing in the browser. And the e-mail [redacted] is not working either.

If you have any insight on this issue, please help me.
I GREATLY appreciate it!