So i believe its a shared hosting.
I would advice on getting a VPS, its much better and u have more control over your server.
However, if your NC is still new, install it via cPanel, and manage your upgrades via cPanel and not the NC admin.
I installed via Cpanel but how do I upgrade with the cpanel? Do I simply substitute all the files for new ones but leave the files with data on them there?
If your cPanel is using Softaculous, then i would assume you installed it from there, if you go back there, you should find update or something like that.
No, I just created a sub domain and installed the files. Can I install Softaculous and use it to upgrade?
nb from Panthur
"I am afraid you only have jailed Shell access this means no Sudo access, The server is a centOS linux installed with cPanel. "
No, you can’t. Its a licensed service your host can buy. How about fantastico?
My advice to you is VPS, NC wont run with its full power under shared hosting, plus it wont be able to manage the transactions.
Get a VPS with Ubuntu 18.04, and you can run the installation via SSH for NC15 with Nginx. Just make sure you have enough ram.
I see that cpanel Installatron now has Nextcloud in the repo- 14.0.3
Can I install this and move my data over from v13?
re: Get a VPS - I could I suppose, but I already have space on my web server and really only need it for syncing contacts, calendar and notes from/to my computer and phone.
I really probably do not even need to update.
No large amounts of data or network to cater to.