If you scan a document your computer simply sees it as a photo. (i.e. all it recognises is blocks of black, white and, if appropriate, colours placed on a page. It doesn't 'see' letters or words). To get a computer to 'translate' the 'photo' into letters and words requires the use of OCR (optical character recognition) software.
So before you can think about sorting a scanned list alphabetically you need to be looking for some OCR software to convert the scanned output from a 'photo' to text. Fortunately Windows 10 comes with Microsoft Document Imaging, which enables you to scan an image and then go to Tools > Send Text To Word, so that's where you need to start.