Did you follow all these steps exactly?
https://codex.ww.wp.xz.cn/Moving_WordPress#Changing_Your_Domain_Name_and_URLs
I’m assuming the domain you changed it to is actually set up to point to his hosting account?
What was the old domain and what is the new domain?
I assume so too? I literally only changed the website name in the Settings page… that’s what I fiddled with
(well there were 2 places for website name change… and since I can’t log back in, I can’t return to the page to see what exactly I’m talking about)
and well…seems that stuff is dealing with the (for example) .com becoming .net …am I understanding this correctly?
the .com part is still .com for the prof; just the name has changed from marsoneflies.com to beacon.com
do I need to have WordPress itself downloaded on my computer?
There is more to changing the domain than just changing those two settings.
Looking at the DNS records for the two domains, they’re not even pointing to the same server, so that’s your first problem.
If you don’t understand what DNS records are and how to go about changing them then you need to find someone who does.
Once you get that issue resolved, then you need to follow all the steps outlined in the article I linked to earlier.
Since you’ve now locked yourself out of the database, you’ll need to use a program like phpMyAdmin and edit the database records directly and change them back to what they were originally.
You do not need to have WordPress installed on your computer.
You sound like you’re in a bit over your head on this. I hope your professor doesn’t take this into account come grading time. 🙂
