As I see your Nginx status it seems port 80 is already being used by another software ( most probably apache ).
In this case, first, you have to remove the apache from your server then try to install Nginx on your server.
First, use these commands to remove the apache
sudo apt remove apache2
then use this command to auto-remove unnecessary things
sudo apt autoremove
and then you can try to install nginx on your ubuntu machine.
or if you already installed use this command to start the nginx .
sudo systemctl start nginx
and now check the nginx status by using this command:
sudo systemctl status nginx
I hope this will help you.