Install LAMP on CentOS 7

First get your system updated
yum update -y; yum upgrade -y
Install LAMP package as below
yum install httpd mariadb-server mariadb php php-mysql -y 
systemctl enable httpd 
systemctl enable mariadb
systemctl start httpd 
systemctl start mariadb
Configure MySQL/MariaDB initial setup.
To install additional PHP package/extension simply search as below
yum search php-
Add http service to firewalld
firewall-cmd --permanent --zone=public --add-service=http 
firewall-cmd --permanent --zone=public --add-service=https
firewall-cmd --reload