NGINX location configuration

Right now I have set up NGINX and had a question regarding the url paths and how NGINX approaches it. Right now, if I do something like /sample.html, it will effectively display sample.html. However, I want to do something where irregardless of what the user inputs in the URL, it displays sample.html. For example, doing something like /network will still display sample.html but will retain the url path of /network. Right now, this is how my NGINX.conf looks like:

 worker_processes  2;

 pid        logs/nginx.pid;
 error_log syslog:server=unix:/dev/log,facility=local7,tag=nginx,severity=error;

 events {
   worker_connections  1024;
 }


 http {
include       mime.types;
default_type  application/octet-stream;

access_log       syslog:server=unix:/dev/log,facility=local7,tag=nginx,severity=info combined;

sendfile        on;
keepalive_timeout  65;


server {
    listen       80;
    server_name  localhost;
        root   /home/user/Downloads/nginx/html;

 location /network {
 index sample.html sample.htm;
    }

    location / {
 index sample.html sample.htm;
        autoindex on;
    }   

    #error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   html;
    }
}
 }

I thought this would work but it is just returning a 404 error. Any idea on how I can change this so that it would work in how I want it to work, if it is possible?

Thank you, and let me know if you need more information!