Some of the wording you have here is a little awkward and off-putting- "In the cement basement there was nothing out of the ordinary here", "the woman with powers of the mystic could flee to cast their spells", " It was not prettily decorated, there were simply wooden shelves lining the ten foot high hole". I think you should play around with word order and word choices to make your sentences flow better.
At one point you use 'stomp' when it should be 'stump', and even a simple spelling error like that turned me off from reading more. I'm hyper-critical of a book in its first few pages, so I would really watch out for any mistakes that early on.
This opening has the potential to be interesting, and as the reader I am already forming ideas about where the story itself will go, but I don't think there is enough sense of your character here. We find out she's twelve, she has an old grandmother, and she might be connected to magic in some sort of way, but these are all background things in my opinion- what's her personality? And there's too much description of the setting without enough to interest us further. It's like we're coming into the basement ourselves, looking around at everything and thinking, well, now what? We shouldn't even have time to think- there should be something to catch our attention and engage us right from the beginning.
I liked your line "The hidden tree stump is my family’s sanctuary." I've always read that a writer should experiment with their first line/paragraph a lot before they figure out what it'll be, and I'd suggest trying to use that line as your starting point, just to see what comes of it. I feel it'd be a much more engaging first line than anything about a basement. Not that I'm saying the first scene *shouldn't* take place there, but you could definitely rework it to make it more exciting.
Hope this helped!