PHP:
https://www.w3schools.com/php/

Java Spring MVC:
https://www.coursera.org/learn/spring-mvc-rest-controller

Java:
https://www.w3schools.com/java/default.asp

Asp.Net MVC
https://www.tutorialsteacher.com/mvc

MYSQL Database
https://www.w3schools.com/php/php_mysql_intro.asp

MS Sql Server
https://www.sqlservertutorial.net/

ASP.NET 4.5
https://learn.microsoft.com/en-us/aspnet/web-forms/overview/getting-started/getting-started-with-aspnet-45-web-forms/introduction-and-overview

React Js
https://www.codecademy.com/learn/react-101

Angular JS
https://www.w3schools.com/angular/default.asp

Full stack JavaScript
https://www.w3schools.com/whatis/whatis_fullstack_js.asp

MERN Stack
https://www.geeksforgeeks.org/mern-stack/