Now that you have a website, you want people to find you.
Once upon a time this was all about setting keywords in meta tags. However, most search engines these days ignore meta tags and just use the text of the main body of the content. In years past, meta tags were heavily abused by people trying to push their pages up the rankings, and the search engines just got better at pulling out the keywords from the main body of the text.
The first thing you should do is to ensure that your content contains terms that interested people might be searching for. The name of your group is an obvious one, and that should already be covered by the home page title. However, your intended audience may not know your name, and may use more generic search terms. So try to describe who you are and what you do as if speaking to an outsider who has never come across you before.
The next step is to try to get other sites to link to yours. Links are one of the primary rating factors for search engines because they indicate that other sites consider your content is worth looking at. If there is an umbrella organisation, or a site that promotes groups nationally or internationally, get your site details onto their site. For Probus clubs this would be probusglobal.org or probusonline.org. You could also try your local library, U3A, or any other local service.
You can also submit your site to the Google search console. If Skirrid Systems is managing your domain name then this will be done for you. If you manage your own domain name then you will need to do this yourself.