Nginx. Config two sites on the same port

I'm trying to add a wikimedia site on my server, which already has another site (which doesn't use PHP) on it. I want to put it on a different folder like www.hostname.com/wiki but it would be wonderful to have two different conf files to avoid mixing stuff. At the moment I'm trying to put this wikimedia site on a different port, the 81, and having some issues.

My nginx.conf looks like this:

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log;
#error_log  /var/log/nginx/error.log  notice;
#error_log  /var/log/nginx/error.log  info;

pid        /run/nginx.pid;

events {
    worker_connections  1024;
}

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

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;
    sendfile        on;
    keepalive_timeout  65;
    index   index.html index.htm index.php;
    include /etc/nginx/conf.d/*.conf;

}

And on the conf.d folder I have two files:

site.conf which looks like this:

server {
    listen 80;

    server_name hostname.com;

    auth_basic "Restricted Access";
    auth_basic_user_file /etc/nginx/htpasswd.users;

    location /kibanaadmin/ {
        proxy_pass http://localhost:5601/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    root /usr/share/nginx/html/pruebas/site;
    index index.php index.html index.htm;

    try_files $uri $uri/ /index.php?$args;

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
    }
}

And wiki.conf file:

server {

        listen 81;

        server_name hostname.com;

        root /usr/share/nginx/html/tests/mediawiki;

        client_max_body_size 5m;
        client_body_timeout 60;

        index index.html index.htm index.php;

        location / {
                try_files $uri $uri/ @rewrite;
                autoindex on;
                index index.html index.html index.php;
        }

        location @rewrite {
                rewrite ^/(.*)$ /index.php?title=$1&$args;
        }

        location ^~ /maintenance/ {
                return 403;
        }

        location ~ \.php$ {
                autoindex on;
                include fastcgi_params;
                fastcgi_pass unix:/tmp/phpfpm.sock;
        }

        location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ {
                try_files $uri /index.php;
                expires max;
                log_not_found off;
        }

        location = /_.gif {
                expires max;
                empty_gif;
        }

        location ^~ /cache/ {
                deny all;
        }

        location /dumps {
                root /usr/share/nginx/html/tests/mediawiki/local;
                autoindex on;
        }
}

I noticed two different problems:

The first one is that when I try to get a php file I get a 502 Bad Gateway and on the error.log I get this message:

2015/07/15 10:56:57 [crit] 16306#0: *6 connect() to unix:/var/run/php-fpm/php-fpm.sock failed (2: No such file or directory) while connecting to upstream, client: 111.222.333.444, server: hostname.com, request: "GET /info.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php-fpm/php-fpm.sock:", host: "hostname.com"

I checked my php config and I'm think is correct, I don't know if it's a nginx config problem or a PHP.

The second problem is that when I go to hostname.com:81 I get and 403 Forbidden (my other site in hostname.com:80 works with no issues) and this log message:

2015/07/15 10:59:15 [error] 16306#0: *9 directory index of

"/usr/share/nginx/html/pruebas/" is forbidden, client: 111.222.333.444, server: hostname.com, request: "GET / HTTP/1.1", host: "hostname.com:81"

My main question is: How can I manage to have the wikimedia site on the port 80 as well as my site but using two conf files of nginx to do it (If is not possible, how can I do it with just one file) and properly config the PHP stuff in nginx?

Note: I think is not a permissions problem because I gave the same to the wikimedia site as the other site has. I'm using Centos 7.1. Thank you in advance.