Thanks for the debugging info and steps you took
What you’ve done means the server is running and DNS/hosts file is working at least.
Here’s the next steps you can take:
vagrant ssh
sudo service nginx status
Hopefully that says it’s not running since that’s easier to debug.
If it’s not running, you can run sudo nginx -t
to see if there’s any configuration issues. And might as well try to run sudo service nginx start
or sudo service nginx restart
and see if that gets it running.