Info about maintaining a website here

The host and branch sites here is a domain name pointing to this host.
Branches have subdomains on this, eg
The code and pages for each subdomain are in one separate directory per subdomain.
Webmasters have access via FTP (File Transfer Protocol) to the directory for their site.
That allows them to upload and download files making up their website.

Suggestions on editing and transferring files

  1. Create an empty directory on your PC which will be the root directory of the website.
  2. Download and install the free FTP transfer program Filezilla on your PC. It is available for all operating systems.
  3. Configure Filezilla to connect to your website using the credentials you have been supplied with.
  4. Connect to the website using Filezilla. Download all the current files on the website to the directory you created for the purpose.
  5. Make a copy of that directory. Keep safe, unchanged.
  6. Edit the files you want to change using a raw text editor or a code editor. Notepad++ is one suitable free editor.
  7. Test the changes locally. Edit until correct.
  8. Upload the changed files to the web server. Test them there to ensure the changes work and are correct.
  9. Copy the 'final' set of files to a new directory as backup for when you next edit, in case you break something, and need to revert to what worked last time. You can never have too many backups. ZIPs of the public_html directory won't take much space unless you have a lot of image and PDF files in it. (Professionals use a file archiving system which allows reverting to any particular version of the code set.)

The directory and file structure

Testing files on your PC

File types

HTML files

This isn't the place to elaborate on what HTML files are and what they contain. There are numerous definitive texts on the web, like
Suffice to say that straight text is written into HTML files, and controlled using tags.

You can see how any HTML page does its magic by right-clicking on the page displayed in your Internet browser, and selecting view page source, or similar.
Copying a technique you find in existing web pages is an easy way to write a page.