I just created a nextcloud server using this guide. (note that it uses snap, not the manual installation)
I am wondering, is it possible to connect it to the outside world?
If it helps, I’m using a 64-bit ubuntu 16.04.
I’m assuming I might have to do port forwarding (even though I have no idea what i am doing) so my router is the ZyXel AMG1302-T10B
To connect your Nextcloud --TO-- the outside world, you do not need anything from your router. You need the external storage module and to configure it to point to the remote storage you wish to connect.
To connect your Nextcloud --FROM-- the outside world you need some kind of port forwarding.
Here is the user manual for your router. On page 46, it explains about port forwarding…
To be accessible from the outside world, you need a server that is on the internet. Of course, with port forwarding you can can configure your home machine as that server. Maybe you need a DynDNS server.
Little hint: While connecting from outside the world to your cloud make sure you install SSL! Letsencrypt with Certbot will help. Otherwise the data traffic is unencrypted and everybody can read your data, even passwords and files