Help: Multiple domains per droplet:

I'm fairly new to Digital Ocean Cloud: https://www.digitalocean.com/?refcode=e9bbe1bb8c6a

and right now I'm trying to set this up. I'm no devops so this is fairly a bit more than my currently knowlege. If you know, can you help:

https://www.digitalocean.com/community/questions/multiple-domains-per-droplet