I can login to a root shell on my machine (yes or no, or I don't know): yes
I had to change ip address but still same domain name. old ip address has https certificate as well. same domain name has two different ip address and https? I detroyed old ip address before I got new one of course. I am just beginner and so many things I don't know.
There isn't anything listening on port 443 which is the port used for HTTPS. So HTTPS is not working right now.
You don't have a HTTP to HTTPS redirect. (Which for now is good of course, as HTTPS isn't working. But when that works, you should implement a HTTP to HTTPS redirect.)
This is just a hint for some reading. Depending on how you got the certificate in the first place this might or might not be exactly what you require. However, as you've not given us much information to work with, I can only provide generic documentation for you to read.