SharePoint allows you to create as many calendars as you like. Each calendar has one or more events. An event is basically an appointment or a series of appointments or calendar item if that term makes more sense. A series just means that it repeats every so often. That could be once a week, daily, monthly, etc. Once you have an event or event series you can may find that you want to track information such as who attended the meeting, the agenda, objectives, etc. You can track all this in what is called a Meeting Workspace. The workspace will show all the information related to an event. Please note, a workspace is NOT linked to a calendar itself. A calendar can have multiple events and each event can have one workspace. If the workspace is related to a event series then the workspace still is linked to an event, but also shows all the events that are in the series in a list of dates on the left side of the workspace.
You can link an event or event series to a Meeting workspace by opening that event or event series on a given calendar. This link describes how to link to a new or existing Meeting workspace. What it does NOT tell is that you can ONLY link to Meeting Workspaces that are BELOW the site that contains your calendar that has the event you are linking to the Meeting workspace. What this means is that if you have a calendar defined in the Meeting workspace itself then you can’t link events on that calendar to that Meeting workspace. You should be able to create a new Meeting workspace below that Meeting workspace, but that doesn’t change the rule I just noted.
A question that came up is “Why is the next event come up by default when I go to the Meeting workspace directly, instead of the last one.” Basically, SharePoint shows the current event if it is the same a today, and will show the next event if the last event has already passed. In general, SharePoint tries to show you the most recent information it has. While this is not always the best, it is by design.