Here is many questions not answered to make this easy, but i'll understand it like you would run your .php on the slow apache and then use the nginx as reversed frontend for apache..... but since you don't know about how to do this, you properly don't have a lot of visitors, so I'll suggest you skip the apache and go directly into nginx with php-fpm and reverse into that
guide for that part is here https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html
Next you'll have to simply fullow the https://nginx.org/en/docs/ to set it up
but..
make a /etc/nginx/conf.d/mysite.conf
make it listen to your ip
open port :80 on the vps and you are close
the most very basic ex. of a conf file looks somewhat like this
server (
listen 155.94.xxx.15x:80;
listen 155.94.xxx.15x:443;
server_name yourdomain.tld www.yourdomain.tld;
root /full/path/to/your/html/files;
index index.php index.html;
}
thi will now serve static *.html files from /full/path/to/your/html/files/ starting with the index.html
guide for that part is here https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html
Next you'll have to simply fullow the https://nginx.org/en/docs/ to set it up
but..
make a /etc/nginx/conf.d/mysite.conf
make it listen to your ip
open port :80 on the vps and you are close
the most very basic ex. of a conf file looks somewhat like this
server (
listen 155.94.xxx.15x:80;
listen 155.94.xxx.15x:443;
server_name yourdomain.tld www.yourdomain.tld;
root /full/path/to/your/html/files;
index index.php index.html;
}
thi will now serve static *.html files from /full/path/to/your/html/files/ starting with the index.html