DIEGO00AQ

I too am running a LEMP. As far as your SQL set up have you created a new user with sudo privileges instead of using “root” every login? If not start with this step first. Following this guide will allow you to create a new sql user and password while protecting your server from mistakenly using root access and creating a mess https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-14-04

After follow this guide for hosting multiple domains in Nginx
https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-server-blocks-virtual-hosts-on-ubuntu-14-04.

It is important you create a directory for each domain preferably using the /var/www/yourdomain.com/html file set up. This will separate your domains allowing you to install Wordpress on one domain and run an static HTML site on another domain in addition to the ability to add more domains within the same droplet. As far as installing Wordpress I recommend downloading to your sever, extract Wordpress and then copy the files directly into your /var/www/yourdomain.com/ I used this guide
http://www.chanhvuong.com/2068/install-ubuntu-lemp-wordpress-unmanaged-vps/.

All in all it took some trial and error but now I am running 2 Wordpress domains and an HTML/CSS domain on one $5 droplet. Hope this helps.