*IF* I was very lucky I might get the chance of a flight.
What was the weather expected to be like?
In my (limited) experience, the days coordinator/duty instructor will try and arrange three flights per person per day. The rest of the time you're supposed to help out on the ground.
If it's a good thermic day, you might only get one or two flights, but those will be 45-60 minutes flights. If it's not thermic at all, you might be able to get in as many as six flights a day, but all will be ~6 minutes.
Obviously in early March there's limited daylight and thus even more limited chance of getting good thermals. But there's also a greater chance of downright horrible weather making flying impossible.
So, no, they do not give you any guarantees about the number of flights but if circumstances permit you should be doing at least three short flights, or one or two longer flights.
As far as the rest of your mail is concerned, yes, gliding is much more a team effort than powered flying. You are expected to be present from the morning briefing onwards until the last aircraft has been cleaned and put in the hangar.