APACHE
If you are using apache only webserver then you can access mod_userdir like this:

http://HOSTNAME.COM/~USERNAME/

example:

http://srv1.google.com/~yahoo/

NGINX
When using nginx you can use mod_userdir only with apache port.

http://HOSTNAME.COM:8181/~USERNAME/

example:

http://srv1.google.com:8181/~yahoo/

Replace
- HOSTNAME.COM with your server hostname or main IP
- USERNAME with the username of the user

Port 8181 is an apache port when using nginx.
You will need to open a firewall for port 8181 if you want to allow that access.

INFO
Note that mod_userdir always opens only the main account path:
/home/username/public_html