How to install next cloud
The documentation could be a starting point:
try one of the playbooks.
or visit: https://www.c-rieger.de/
or google “nextcloud howto”
You don’t need to speak Spanish, just follow the order and you can install it on Debian 10.
Please don’t do that. It’s a very bad idea to type commands blindly. You should know what you are doing, when you are at steps with different options and where you have possibilities to ask when you have doubts. There are enough manuals in English (and other languages). Just make sure it is not too old and fits your system.
Many manual make it seem easy to install Nextcloud, however taking some time and going through a few things in the beginning is way better than learning it later the hard way (after a data loss because of a missing backup etc.). Give yourself some time and a testing period.
I second this. You more than likely arrived here after following flawed instructions that did not produce the expected result. Pasting commands blindly from instructions you can’t even read could be disastrous.