There are several free websites available for creating your writing group webpage. WordPress.com is one of them. Another simple method is to just add a page to your existing author website.
In my personal opinion, your writing group webpage should be very simple. There’s no need to create page after page of content. If your members have questions, they can ask in person at the next meeting.
The only thing you really need is the what, where and when. Provide a description of what your writing group does, where they meet and on what day and time. That’s all you need.
However, keep your search engine optimization in mind and try to use phrases that prospective participants will use while searching for your group online.