Cpanel to Webmin migration 503 error

Hi, web-brackets forum members! It's a pleasure to join your forum.

Here's my problem: I'm trying to migrate my hosting servers from shared hosting to VPS. I'm using WordPress and Cpanel. Here are the steps I took and what happened afterward:

1. I made a full account backup in my Cpanel.
2. I created a new server on Virtualmin.
3. I uploaded the backup and followed the steps in this guide
4. Everything seemed to migrate with no errors, but when I try to preview my site I get the following error:
   Service Unavailable The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later. 503 Service Unavailable.

I have a guess what might have gone wrong - when I made the backup I had to enter my Cpanel credentials to Virtualmin when installing the backup. But I had forgotten my password to log in to Cpanel, so I reset it and set a new one (there was some kind of text about database passwords, but I accidentally closed the tab and missed what it said). So my guess is that maybe after changing the Cpanel password, I had to change the password in the backup files as well?