Lets start with the simplest one: HTML
HTML is a very common type of coding on the internet, used in most webpages, and tends to be the simplest to learn. In order to understant HTML coding, you need to learn about some basic commands used when making an HTML websites, all HTML websites must start with <!DOCTYPE html>, this lets the system know that the website about to be created is an HTML site, the site itself after <!DOCTYPE html> should start with <html> at the very end of your site you need to put </html>, but you need to put everything else in between those 2 commands.The space in between these commands usually starts with <body> and ends with </body>, these 2 commands tell the system that this will be the body of you're webpage, telling it to show this once the website is opened, once thats done, you can finally move on to putting words on your webpage. The first thing you'll want to put between <body> and </body> is going to be <h1> and </h1>, that tells the system your making your header, anything you put between <h1 and </h1> will be bigger than normal text. After thats finished, you'll want to put <p> and </p>, these 2 commands don't go between <h1> and </h1>, instead, they can be put anywhere as long as they are between <body> and </body>, <p> and </p> stands for paragraph, which is going to be your normal text, it's smaller than the header as they header should be much like a title and seen before the paragraph. You can adjust the size of your heading by changing the number in the code: <h1></h1> is the biggest, and <h6></h6> is the smallest. You can also use HTML to add links, for a link, you'll use <a> and </a>, also, you must always follow <a with href=, for example:
<a href="www.html.com">www.html.com</a>