Where can I download the App Store

I'm honestly mad right now. I've been trying to find my App Store so I can update my computer so I can restore my iPad that suddenly stopped working. Nothing can ever be easy for me so of course the App Store on my computed is gone. Missing. Deleted. apple can't be nice and just have a download button for it so now I have a useless iPad and I'm extremely frustrated! Can someone please tell me where I can download the Mac App Store?