Building Rabbit Holes

[chair24]

Hi everyone, it's my first post so nice to meet you all!

Sorry, I'm a bit of a rookie with The Sims 3 but would like to learn more and think this is a pretty good place to start!

I am trying to figure out how to make a rabbit hole for a school (currently). I assume that I make a "No visitors allowed" plot in Create a World tool and then in game under edit town I can put a shell of a school in this plot. Is that all I do to make a school...as in a place where the kids can go to learn? If I do that I just get a community symbol appear on the plot, not like a school symbol.

I am guessing this is very simple for 99% of you so if any of you could steer me in the right direction, I'd be very grateful. I have all of the expansion packs if that makes any difference.

Many thanks!