Hello!

I am starting my journey as a developer and building a simple website for an NGO.
I am able to code in Ruby on Rails and some basic Javascript (in addition to HTML and CSS) but am thinking to ditch JS to make it lighter.

The only requirement would be that the client should be able to modify the content without my intervention (update events section, add articles or modify some info of the website).

On the optional preferred aspects would be a very light-weight website (I'm interested in delving into sober, more eco-friendly web development, any resources on that would be appreciated too!), as open-source and cheap as possible and obviously as easily maintainable as possible. Scalability isn't required.
Although very unfamiliar with the deployment and hosting aspects (I only learned Heroku during my bootcamp), I have seen Hugo could be a good option for this since there's no need for dynamically generated content (just the introductory page of the NGO, upcoming and past events and latest scientific publications by the NGO (short article, text only) but I'm a bit lost and would like some advice.

Thank you very much!