Configure Ubuntu SSH Access

I have just spun up a fresh Ubuntu VPS and I’m tightening it for production. Right now I can only log in as root over SSH (password-based authentication) and I’ve hit a wall creating a non-root account that can actually log in.

Here’s where I need your help:
• Create a new user called “jim” with a proper /home/jim directory, correct ownership and permissions.
• Ensure that jim can log in via SSH (still password-based for now) and, once connected, can su to root while being blocked from all sudo commands.
• Disable direct root logins over SSH.
• Move sshd to a non-standard port to cut down on brute-force noise.
• Verify the entire flow end-to-end so I can reproduce the steps later if I rebuild the server.

When I try to SSH as a test user I get no specific error—just a failure to log in—so I suspect something’s off with the home directory or PAM settings, but I’m not sure how to check.

I will provide temporary root SSH access to the server. Please document each command or config change so I can keep the hardening playbook up to date.