Issues with setting up port Ubuntu 18.xx

hello guys

I am really get done with this issue and really it concerns me a lot especially i decided to convert to erpnext, I am using oracle VM ubuntu 18.xx and i install every thing (i guess Correctly) and i setup my site on port 8000,
bench config dns_multitenant on

Set port

bench set-nginx-port site_name 8000
bench setup nginx
sudo service nginx reload

but i could not lunch my site without this command

nohup bench --site my_site serve --port 8000 and this command must be run background to be able to log and and i must run bench start command too
i have another site with port 1291 and the same thing
meanwhile on localhost:80 i get this message

Welcome to nginx!
If you see this page, the nginx web server is successfully installed and working. Further configuration is required.

For online documentation and support please refer to nginx.org.
Commercial support is available at nginx.com.

Thank you for using nginx.

please advise I do not wanna face losing data in future i am afraid that some day i won’t be able to access my site

@Ham also remove default site from current_site.txt.

thanks for reply
i removed the sites from current_site.txt and nothing happend it didn’t work

From your config your are setting up for port 8000

bench set-nginx-port site_name 8000
bench setup nginx
sudo service nginx reload

but then you are browsing to port 80 (localhost:80) instead of http://localhost:8000

no sir i browse for port 8000 of-course but yet i can’t open the site with this command
bench --site my_site serve --port 8000

please i want i quick solution because i am converting to erpnext

Can you see if the port is active?

netstat -tnlp | grep -i listen

After changing ports, you normally need to restart nginx

systemctl restart nginx