if you want to store data on program use this :
$name "vijay";
$num 32;
$name or $num indicates the variable names you can give any name for variable ex $variable_name
if you want to store data permanently you have to use database
This is explained pretty broadly throughout the entire course. Theres a lot of ways to store data, but basically youre assigning a value to a variable.
Examples
int x=36
int y="hello"
