Cloud Based Application (With Private Login Page)

Hello,

I currently have a website its tidalbookings.com

I want to be able to upload a cloud based application I have made to this domain, But I would like it to have a private access page like this

http://manager.likestagram.com/login

I would also like the application dashboard to be under the domain name manager.tidalbookings.com

Can you guys please help me on how to do this!

Thanks!