I am looking for knowledge - firewall ubuntu

[HiddenDeveloper]

Hi, i found many different tutorials about ports.
Someone can explain me which one i have to choose and why?

He is a list of my commands (all also with wrong ufw allow commands, i need to understand how http, https, ssh, mariadb, client-server works on correct ports)

sudo ufw allow OpenSSH

sudo ufw allow in "Nginx Full"

sudo ufw enable

sudo ufw status

sudo ufw reload


sudo ufw allow 7171
sudo ufw allow 7172

sudo ufw allow 22/tcp
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw allow 3306/tcp

sudo systemctl enable ufw
sudo systemctl start ufw
sudo ufw default deny incoming
sudo ufw default allow outgoing

sudo systemctl restart ufw

sudo ufw reload

Its important? what is best option to choose, what to avoid?