So I have been following the instructions

(https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-phpmyadmin-on-ubuntu-18-04)

for installing myphpadmin and after completing the last step I tried to launch the url with:
http://your_domain_or_IP/phpmyadmin

All I got was a 404 error. When I tried to go back into PuTTY to find out what was wrong. This is when mysql started returning

ERROR 1045 (28000): Access denied for user ‘user’@'localhost’ (using password: NO)

I can get into mysql with “mysql -u root -p” and there don’t seem to be any issues once I am in there.
I am incredibly new to this so I apologize if I am not providing some important information.
My end goal is to upload an html file to the url I have. I have done all of the tutorials for apache, python, pip.