You cannot just like that add a string. You need to enclose them in a string first.
$var1 = "'Text here'"; // Enclose this way.
$var2 = $var1;
echo $var2;
In your understanding, using the following code will give you an error.
$var = Hello World; // Error
In normal ways, a string can be defined by:
$var = "Hello World"; // or
$var = 'Hello World';
If you need to include quotes, you can also use escape characters. See Escaping quotation marks in PHP.
$var = "Hello \"Real\" World!";
And in your case, it could be:
$var1 = '\'Text here\'';
Another interesting way is:
$var1 = 'Text here';
$var2 = "'$var1'";