Small online bookshop requires stock management db setup

My inventory is currently stored in 1 table. My sales report is downloaded from my website in excell.

I want to use the list of book numbers on the sales report to automatically generate a picking list (a basic VLOOKUP?) with info from some columns in the db and some in the downloaded file.

In addition I want this list of book numbers from the downloaded report to reduce the quantities of the respective book in the db, with timestamp added.

I do also have some other more complicated things in mind, but wish to leave that for now until I get used to working with what I get from this project first.