How i can use php for make changing data on mysql?

Answer 1

create a connection with
$conn = new mysqli($servername, $user, $pass, $dbname);
and make your queries

$conn->query("update customer set salary = 1 where id = 1");

Answer 2

you can enter this website and click on LearnSQL or download solo learn SQL and you can know how and for the website the URL is www.w3schools.com