Editing a Web Page (sometimes written web page or webpage) is different to viewing them. For viewing you will most likely use a Web Browser such as Chrome, Firefox, Edge, Opera etc. or one of the many other browsers available. For editing a web page you also have various options which will often be dependent on which platform you are using.
This guide is going to focus on using Notepad++ on a Windows 10 PC. It is not part of 'standard' Windows so will need installing (unless someone has already done this for you). It is a text editor (like Notepad) but with more features suitable for editing code (e.g. Python) and markup (e.g. HTML). If necessary, you can use Notepad without the syntax highlighting etc. but be careful it does not trick you into adding '.txt' to the end of your files. Also note that you should not use a Word Processor like Word to edit code or markup because they save in their own file formats and although Word may be made to edit a web page it can get unnecessarily complicated quickly.
A web page is written in HyperText Markup Language (HTML). Usually by default if you double click on a HTML file it opens it in a browser. This is what you should do first. It means you can view the result of your markup changes. Once open in a browser, go back to the File Explorer and right click on the same file and choose the option to edit with Notepad++. You should then have two versions of the same page. One which looks like code and one that looks like a website.
NOTE: If you have downloaded the template from Putkeep, you need to unzip it and move it to your documents before you open it for viewing and editing otherwise you will have problems further down the line.