Password-protected calendar editable by club members

I’m a member of a small club that has a handful of sailboats available to a dozen members and would like to develop a very simple reservation system and make it available on my website or on the club’s website. So I’m thinking about a spreadsheet calendar page whereby a member can sign in to the page and initial his reservation slots on an honor system basis. Can anybody here point me to anything? My WordPress site is sbranch.org and my webhost is Godaddy. I know only basic html, but I have had the site for several years. I will try to put a jpg on my site that represents the sort of page I have in mind so you can look at the dummy prototype.

Thanks in advance for any help.