This is a big environment for you, at least you should know the comings and goings and the priorities.
So I can't give you a theory here.
But relatively speaking, it is not urgent.
It is recommended to hire a master to explain it to you on the spot.
But if it's an old house, it's hard to say whether there was an owner before.
Because the current teachers are very miscellaneous, most students who take the self-taught exam basically don't know how to do it.
There are genuine products, which are hard to see after use.