I really hate it when you follow numerous scripts to install something and they all seem to get it wrong. Here is what worked for me:

Ubuntu 20.04 [this will install the latest php version that is in the repo

apt install apache2 php php-pear php-fpm php-dev php-zip php-curl php-xmlrpc php-gd php-mysql php-mbstring php-xml libapache2-mod-php mysql-server

mysql_secure_installation

in mysql [they all got this wrong - you cannot create a user and grant permissions at the same time anymore]

create user 'joomla_user'@localhost identified by 'password';
create database joomla;
grant all on joomla* to joomla_user@localhost;
flush privileges;
exit;

mkdir /var/www/html/joomla
copy program to dir and untar/zip
chown -R www-data:www-data /var/www/html/joomla
chmod -R 755 /var/www/html/joomla