After installing Ghost on a new account, I might be able to visit the homepage once - but I can't login to Admin before everything starts to give me a 503 error.
How can I fix this? Do I need to restart Ghost through command line?
It looks like for some reason the node.js service is crashing. Can you please open a support ticket with the control panel login details so that we can check the issue :
https://www.softaculous.com/support/
You can Start/Stop/Restart the node.js service from the Edit Installation page in Softaculous.