Help me please...How can i selected colums and row from air table with table that I make on design app? how to add and reduce data that can update to airtable

I wanna make an apk (medicine stock apk) that contain name of medicine, date that stock it and the total stock of medicine using airtable, how to make the code of reduce data (when someone take the medicine, so the number of the medicine stock reduce according to the how many the took the medicine)
How to put the row that we choose to the label?
sorry for my bad grammar…I hope you will understand what I mean and help me fast