localhost上的示例PHP页面显示一个空白页面

I follow this guide to setup a sample WordPress site on my Linux machine. The packages are changed to the newer php7.2-gd, php7.2-curl, and libssh2-php. My /etc/nginx/sites-available/davewordpress file is as follow:

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    root /var/www/wordpress;
    index index.php index.html index.htm;
    server_name localhost;

    location / {
        #try_files $uri $uri/ =404;
        try_files $uri $uri/ /index.php?q=$uri&$args;
    }

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }

    location ~\.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
    }
}

After creating the davewordpress link in /etc/nginx/sites-enabled and restarting nginx and php7.2-fpm, my localhost gives a blank page. What have I done wrong?

OK, I run into this link while searching for the solution, and it really helps by pointing to the location ~ \.php$ block. I comment out two lines and have it working. That blocks now looks like this:

    location ~ \.php$ {     
    #try_files $uri =404;
    include snippets/fastcgi-php.conf;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
    #fastcgi_index index.php;
    include fastcgi_params;
    }

Using sudo nginx -t, the first line reports this problem:

"try_files" directive is duplicate in /etc/nginx/snippets/fastcgi-php.conf:5

The second line reports this problem:

"fastcgi_index" directive is duplicate in /etc/nginx/sites-enabled/u1804wordpress:27

Glad to finally figure it out. I understand the first error. However, can anybody explain to me the second one?