You will be able to build your site, without knowing HTML or PHP. This site (freeguppy.org) offers you a short introduction to the functions offered by the tool, in its standard version. However, GuppY is extensible via plugins, forks, and skins that are developed and proposed by the community of GuppY users. These extensions will
allow you to simply customise your site, and adapt it to your specific needs.

To help you, an abundant amount of documentation is available on this site. If you do not find the answers to your questions, in the documentation, a very active forum (for mutual aid) is also available for your questions.

Use GuppY and focus on what will make your site a success: its contents!