To install LAMP server using tasksel

tasksel-lampserver.txt

$ sudo tasksel install lamp-server

MySQL Secure Installation: 
mysql_secure_installation 


Firewall Configuration:
Enable firewall:
$ sudo ufw enable

Allow Apache:
$ sudo ufw allow in "Apache Full"


Appendix: LAMP install error messages:
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message
Change your server IP or Domain name accordingly
$ sudo bash -c "echo ServerName x.x.x.x >> /etc/apache2/apache2.conf"

Install Phpmyadmin:
$sudo apt install phpmyadmin

    <Directory /var/www/html/>
            AllowOverride All
            Require all granted
    </Directory>