web development courses links to learn for free

web development course comprises of following major scripting languages.

HTML and CSS

HTML is the standard markup language for Web pages. It defines the meaning and structure of web content. Other technologies besides HTML are generally used to describe a web page's appearance/presentation (CSS). Cascading Style Sheets (CSS) is a simple mechanism for adding style (e.g., fonts, colors, spacing) to Web documents.

• https://youtu.be/UB1O30fR-EE - Basic crash course on HTML to get you started to web development very fast.
• https://youtu.be/yfoY53QXEnI - Basic crash course on CSS to get you started to web development very fast.

The above two courses are for very beginners. Never try to stick only to the tutorials. Just follow along it and keep trying new stuffs on your own.

• https://www.youtube.com/playlist?list=PLillGF-RfqbZTASqIqdvm1R5mLrQq79CU - Full playlist on HTML and CSS.

It's not always a good idea to watch only video tutorials. Always try to read the official documentation. That will be very effective and proper way of approach.

• https://www.w3schools.com/ - It's the best source for everything I will say(not always though).
• Other sources - https://www.youtube.com/playlist?list=PL4cUxeGkcC9ivBf_eKCPIAYXWzLlPAm6G

https://www.youtube.com/playlist?list=PLWKjhJtqVAbl1AfjiGyYxwpdAPi5v-1OU

JavaScript (including j Query)

JavaScript is a very crucial part to learn. It makes the website dynamic without the server side communication. It runs immediately on client-side.

• https://youtu.be/Qqx_wzMmFeA - A very basic tutorial to take you through java script.
• https://www.w3schools.com/js/ 
• https://www.javascript.com/learn 
• https://www.youtube.com/playlist?list=PLillGF-RfqbYJVXBgZ_nA7FTAAEpp_IAc - j Query
• https://www.youtube.com/playlist?list=PL6n9fhu94yhVDV697uvHpavA3K_eWGQap - j Query

Try to learn some libraries of java script where you will find some beautiful implementations.

• https://www.youtube.com/playlist?list=PLRqwX-V7Uu6Zy51Q-x9tMWIv9cueOFTFA - p5.js
• https://youtu.be/POX3dT-pB4E - type.js
• https://youtu.be/qK3cgD09Qf0 - particle.js 

Bootstrap ( 3 or above)

Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS- and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.

• https://www.w3schools.com/bootstrap/bootstrap_get_started.asp
• https://youtu.be/5GcQtLDGXy8
• https://youtu.be/9cKsq14Kfsw - It's a follow along tutorial for making a responsive website using HTML, CSS and Bootstrap.

PHP, MySQL, AJAX

PHP is a core for webpage to store the database of your website and webpages.

• https://youtu.be/OK_JCtrrv-c - PHP
• https://www.geeksforgeeks.org/php-program-fetch-data-localhost-server-database-using-xampp/amp/#aoh=15870175848989&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s Basic PHP MySQL setup.
• https://www.w3schools.com/php/php_ajax_database.asp - Some examples where you can learn some PHP, MySQL and Ajax commands by following up.

Backend is very vast.